import java.io.*;
import java.math.BigInteger;
import java.util.*;

public class D {

    int toInt(String s){
        int h=(s.charAt(0)-'0')*10+s.charAt(1)-'0';
        int m=(s.charAt(3)-'0')*10+s.charAt(4)-'0';
        int ss=(s.charAt(6)-'0')*10+s.charAt(7)-'0';
        return (h*60+m)*60+ss;
    }

    class Pair{
        int id;
        int time;

        public Pair(int id, int time) {
            this.id = id;
            this.time = time;
        }
    }

    void solve() throws IOException {
        int n=nextInt();
        int m=nextInt();
        int t=nextInt();
        int[] a=new int[n];
        for(int i=0;i<n;i++)a[i]=toInt(nextToken());
        int[] q=new int[n];
        int[] ans=new int[n];
        boolean reached=false;
        int count=0;
        int last=-1;
        int j=0;
        for(int i=0;i<n;i++){
            while(j<i){
                if(a[j]+t-1<a[i]){
                    if(q[ans[j]]==j)count--;
                    j++;
                }
                else break;
            }
            if(count==m){
                ans[i]=last;
                q[last]=i;

            }
            else{
                count++;
                ans[i]=++last;
                q[last]=i;
            }
            if(count==m)reached=true;
        }
        if(!reached){
            out.println("No solution");
        }
        else{
            out.println(ans[n-1]+1);
            for(int i=0;i<n;i++)out.println(ans[i]+1);
        }
    }

    public static void main(String[] args) throws IOException {
        new D().run();
    }

    void run() throws IOException {
        reader = new BufferedReader(new InputStreamReader(System.in));
//      reader = new BufferedReader(new FileReader("input.txt"));
        tokenizer = null;
        out = new PrintWriter(new OutputStreamWriter(System.out));
//      out = new PrintWriter(new FileWriter("output.txt"));
        solve();
        reader.close();
        out.flush();

    }

    BufferedReader reader;
    StringTokenizer tokenizer;
    PrintWriter out;

    int nextInt() throws IOException {
        return Integer.parseInt(nextToken());
    }

    long nextLong() throws IOException {
        return Long.parseLong(nextToken());
    }

    double nextDouble() throws IOException {
        return Double.parseDouble(nextToken());
    }

    String nextToken() throws IOException {
        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
            tokenizer = new StringTokenizer(reader.readLine());
        }
        return tokenizer.nextToken();
    }
}


import java.io.*;
import java.math.BigInteger;
import java.util.*;

public class D {

    int toInt(String s){
        int h=(s.charAt(0)-'0')*10+s.charAt(1)-'0';
        int m=(s.charAt(3)-'0')*10+s.charAt(4)-'0';
        int ss=(s.charAt(6)-'0')*10+s.charAt(7)-'0';
        return (h*60+m)*60+ss;
    }

    class Pair{
        int id;
        int time;

        public Pair(int id, int time) {
            this.id = id;
            this.time = time;
        }
    }

    void solve() throws IOException {
        int n=nextInt();
        int m=nextInt();
        int t=nextInt();
        int[] a=new int[n];
        for(int i=0;i<n;i++)a[i]=toInt(nextToken());
        int[] toExit=new int[n];
        LinkedList<Pair> q=new LinkedList<Pair>();
        int[] ans=new int[n];
        boolean reached=false;
        int count=0;
        int last=-1;
        for(int i=0;i<n;i++){
            while(!q.isEmpty()){
                Pair cur=q.peek();
                if(cur.time<a[i]){
                    if(cur.time==toExit[cur.id])count--;
                    q.poll();
                }
                else break;
            }
            if(count==m){
                ans[i]=last;
                q.add(new Pair(last,a[i]+t-1));
                toExit[last]=a[i]+t-1;
            }
            else{
                count++;
                ans[i]=++last;
                q.add(new Pair(last,a[i]+t-1));
                toExit[last]=a[i]+t-1;
            }
            if(count==m)reached=true;
        }
        if(!reached){
            out.println("No solution");
        }
        else{
            out.println(ans[n-1]+1);
            for(int i=0;i<n;i++)out.println(ans[i]+1);
        }
    }

    public static void main(String[] args) throws IOException {
        new D().run();
    }

    void run() throws IOException {
        reader = new BufferedReader(new InputStreamReader(System.in));
//      reader = new BufferedReader(new FileReader("input.txt"));
        tokenizer = null;
        out = new PrintWriter(new OutputStreamWriter(System.out));
//      out = new PrintWriter(new FileWriter("output.txt"));
        solve();
        reader.close();
        out.flush();

    }

    BufferedReader reader;
    StringTokenizer tokenizer;
    PrintWriter out;

    int nextInt() throws IOException {
        return Integer.parseInt(nextToken());
    }

    long nextLong() throws IOException {
        return Long.parseLong(nextToken());
    }

    double nextDouble() throws IOException {
        return Double.parseDouble(nextToken());
    }

    String nextToken() throws IOException {
        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
            tokenizer = new StringTokenizer(reader.readLine());
        }
        return tokenizer.nextToken();
    }
}


import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Scanner;

public class D {

    static void solve() throws IOException {
        String[] nmt = in.readLine().split( " " );
        int n = Integer.parseInt(nmt[0]);
        int m = Integer.parseInt( nmt[1] );
        int t = Integer.parseInt( nmt[2] );
        Integer[] e = new Integer[2 * n];
        for ( int i = 0; i < n; i ++ ) {
            char[] c = in.readLine().toCharArray();
            e[i] = ( ( c[0] - '0' ) * 10 + c[1] - '0' ) * 60 * 60 +
                    ( ( c[3] - '0' ) * 10 + c[4] - '0' ) * 60 +
                    ( c[6] * 10 + c[7] );
            e[n + i] = -( e[i] + t - 1 );
        }
        Arrays.sort(e, new Comparator<Integer>() {
            @Override
            public int compare( Integer i, Integer j ) {
                int r = Integer.compare( Math.abs( i ), Math.abs( j ) );
                if ( r != 0 ) {
                    return r;
                }
                return -Integer.compare( i, j );
            }
        });
        int[] u = new int[n];
        int[] ig = new int[n];
        int lig = 0;
        int rig = 0;
        boolean ok = false;
        int user = 0;
        for ( int i = 0, c = 0, s = 0, prev = -1; i < 2 * n; i ++ ) {
            if ( e[i] >= 0 ) {
                if ( s < m ) {
                    s ++;
                    if ( s == m ) {
                        ok = true;
                    }
                    u[c ++] = user ++;
                } else {
                    u[c ++] = user - 1;
                    ig[rig ++] = -( prev + t - 1 );
                }
                prev = e[i];
            } else {
                if ( lig < rig && ig[lig] == e[i] ) {
                    lig ++;
                    continue;
                }
                s --;
            }
        }
        if ( ! ok ) {
            out.println( "No solution" );
        } else {
            out.println( user );
            for ( int i = 0; i < n; i ++ ) {
                out.println( u[i] + 1 );
            }
        }
    }

    static BufferedReader in;
//    static StreamTokenizer in;
    static PrintWriter out;

//    static int nextInt() throws IOException {
//        in.nextToken();
//        return ( int ) in.nval;
//    }

    public static void main( String[] args ) throws IOException {
        in = new BufferedReader( new InputStreamReader( System.in ) );
        out = new PrintWriter( System.out );
        solve();
        out.close();
    }
}


import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Scanner;

public class D {

    static void solve() throws IOException {
        String[] nmt = in.readLine().split( " " );
        int n = Integer.parseInt(nmt[0]);
        int m = Integer.parseInt( nmt[1] );
        int t = Integer.parseInt( nmt[2] );
        Integer[] e = new Integer[2 * n];
        for ( int i = 0; i < n; i ++ ) {
            char[] c = in.readLine().toCharArray();
            e[i] = ( ( c[0] - '0' ) * 10 + c[1] - '0' ) * 60 * 60 +
                    ( ( c[3] - '0' ) * 10 + c[4] - '0' ) * 60 +
                    ( c[6] * 10 + c[7] );
            e[n + i] = -( e[i] + t - 1 );
        }
        Arrays.sort(e, new Comparator<Integer>() {
            @Override
            public int compare( Integer i, Integer j ) {
                int r = Integer.compare( Math.abs( i ), Math.abs( j ) );
                if ( r != 0 ) {
                    return r;
                }
                return -Integer.compare( i, j );
            }
        });
        int[] u = new int[n];
        int[] ig = new int[n];
        int lig = 0;
        int rig = 0;
        boolean ok = false;
        int user = 0;
        for ( int i = 0, c = 0, s = 0; i < 2 * n; i ++ ) {
            if ( e[i] >= 0 ) {
                if ( s < m ) {
                    s ++;
                    if ( s == m ) {
                        ok = true;
                    }
                    u[c ++] = user ++;
                } else {
                    u[c ++] = user - 1;
                    ig[rig ++] = -( e[i] + t - 1 );
                }
            } else {
                if ( lig < rig && ig[lig] == e[i] ) {
                    lig ++;
                    continue;
                }
                s --;
            }
        }
        if ( ! ok ) {
            out.println( "No solution" );
        } else {
            out.println( user );
            for ( int i = 0; i < n; i ++ ) {
                out.println( u[i] + 1 );
            }
        }
    }

    static BufferedReader in;
//    static StreamTokenizer in;
    static PrintWriter out;

//    static int nextInt() throws IOException {
//        in.nextToken();
//        return ( int ) in.nval;
//    }

    public static void main( String[] args ) throws IOException {
        in = new BufferedReader( new InputStreamReader( System.in ) );
        out = new PrintWriter( System.out );
        solve();
        out.close();
    }
}


import java.util.*;
import java.io.*;

public class D
{
   public static void main(String[] args)
   {
      PrintWriter out = new PrintWriter(System.out);
      new D(new FastScanner(), out);
      out.close();
   }

   public D(FastScanner in, PrintWriter out)
   {
      int N = in.nextInt();
      int M = in.nextInt();
      int T = in.nextInt();
      int[] time = new int[N];
      for (int i=0; i<N; i++)
      {
         String[] ss = in.next().split(":");
         int v = 60*(Integer.parseInt(ss[1])+Integer.parseInt(ss[0])*60)+Integer.parseInt(ss[2]);
         time[i] = v;
      }

      int id_cnt = 1;
      int last_id = -1;
      int[] res = new int[N];
      boolean didPassed = false;
      ArrayDeque<Integer> activeTimes = new ArrayDeque<>();
      int ptr = 0;
      for (int t : time)
      {
         while (activeTimes.size() > 0 && activeTimes.peekFirst().intValue() <= t)
            activeTimes.pollFirst();

         if (activeTimes.size()+1 > M)
         {
            activeTimes.pollLast();
            res[ptr++] = last_id;
         }
         else
         {
            last_id = res[ptr++] = id_cnt++;
         }
         activeTimes.addLast(t+T);

         if (activeTimes.size() == M)
            didPassed = true;
      }

      if (didPassed)
      {
         out.println(id_cnt-1);
         for (int r : res)
            out.println(r);
      }
      else
      {
         out.println("No solution");
      }
   }
}

class FastScanner{
   private InputStream stream;
   private byte[] buf = new byte[1024];
   private int curChar;
   private int numChars;

   public FastScanner()
   {
      stream = System.in;
   }

   int read()
   {
      if (numChars == -1)
         throw new InputMismatchException();
      if (curChar >= numChars){
         curChar = 0;
         try{
            numChars = stream.read(buf);
         } catch (IOException e) {
            throw new InputMismatchException();
         }
         if (numChars <= 0)
            return -1;
      }
      return buf[curChar++];
   }

   boolean isSpaceChar(int c)
   {
      return c==' '||c=='\n'||c=='\r'||c=='\t'||c==-1;
   }

   boolean isEndline(int c)
   {
      return c=='\n'||c=='\r'||c==-1;
   }

   int nextInt()
   {
      return Integer.parseInt(next());
   }

   long nextLong()
   {
      return Long.parseLong(next());
   }

   double nextDouble()
   {
      return Double.parseDouble(next());
   }

   String next(){
      int c = read();
      while (isSpaceChar(c))
         c = read();
      StringBuilder res = new StringBuilder();
      do{
         res.appendCodePoint(c);
         c = read();
      }while(!isSpaceChar(c));
      return res.toString();
   }

   String nextLine(){
      int c = read();
      while (isEndline(c))
         c = read();
      StringBuilder res = new StringBuilder();
      do{
         res.appendCodePoint(c);
         c = read();
      }while(!isEndline(c));
      return res.toString();
   }
}


import static java.lang.Math.*;
import java.util.*;
import java.io.*;

public class D {

	public void solve() throws Exception {

		int n = nextInt(), m = nextInt(), t = nextInt();
		LinkedList<Long> open = new LinkedList<Long>();
		int idmax = 1;
		boolean ok = false;
		LinkedList<Integer> res = new LinkedList<Integer>();
		for (int i=0; i<n; ++i) {
			String[] s = nextLine().split(":");
			int start = Integer.parseInt(s[0]) * 3600 + Integer.parseInt(s[1]) * 60 + Integer.parseInt(s[2]);
			while (!open.isEmpty() && (open.peek() & ((1<<30)-1)) <= start) open.poll();
			long id = open.size() >= m ? (open.removeLast() >> 30) : idmax++;
			res.add((int)id);
			open.add((id<<30) | (start+t));
			if (open.size()==m) ok = true;
		}
		if (!ok) {
			println("No solution");
		} else {
			println(idmax-1);
			for (int id: res) println(id);
		}

	}

	////////////////////////////////////////////////////////////////////////////

	boolean showDebug = true;
	static boolean useFiles = false;
	static String inFile = "input.txt";
	static String outFile = "output.txt";

	double EPS = 1e-7;
	int INF = Integer.MAX_VALUE;
	long INFL = Long.MAX_VALUE;
	double INFD = Double.MAX_VALUE;

	int absPos(int num) {
		return num<0 ? 0:num;
	}
	long absPos(long num) {
		return num<0 ? 0:num;
	}
	double absPos(double num) {
		return num<0 ? 0:num;
	}

	int min(int... nums) {
		int r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]<r) r=nums[i];
		return r;
	}
	int max(int... nums) {
		int r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]>r) r=nums[i];
		return r;
	}
	long minL(long... nums) {
		long r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]<r) r=nums[i];
		return r;
	}
	long maxL(long... nums) {
		long r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]>r) r=nums[i];
		return r;
	}
	double minD(double... nums) {
		double r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]<r) r=nums[i];
		return r;
	}
	double maxD(double... nums) {
		double r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]>r) r=nums[i];
		return r;
	}

	long sumArr(int[] arr) {
		long res = 0;
		for (int i=0; i<arr.length; ++i)
			res+=arr[i];
		return res;
	}
	long sumArr(long[] arr) {
		long res = 0;
		for (int i=0; i<arr.length; ++i)
			res+=arr[i];
		return res;
	}
	double sumArr(double[] arr) {
		double res = 0;
		for (int i=0; i<arr.length; ++i)
			res+=arr[i];
		return res;
	}

	long partsFitCnt(long partSize, long wholeSize) {
		return (partSize+wholeSize-1)/partSize;
	}

	boolean odd(long num) {
		return (num&1)==1;
	}

	boolean hasBit(int num, int pos) {
		return (num&(1<<pos))>0;
	}

	boolean isLetter(char c) {
		return (c>='a' && c<='z') || (c>='A' && c<='Z');
	}
	boolean isLowercase(char c) {
		return (c>='a' && c<='z');
	}
	boolean isUppercase(char c) {
		return (c>='A' && c<='Z');
	}
	boolean isDigit(char c) {
		return (c>='0' && c<='9');
	}

	boolean charIn(String chars, String s) {
		if (s==null) return false;
		if (chars==null || chars.equals("")) return true;
		for (int i=0; i<s.length(); ++i)
			for (int j=0; j<chars.length(); ++j)
				if (chars.charAt(j)==s.charAt(i)) return true;
		return false;
	}

	String stringn(String s, int n) {
		if (n<1 || s==null) return "";
		StringBuilder sb = new StringBuilder(s.length()*n);
		for (int i=0; i<n; ++i) sb.append(s);
		return sb.toString();
	}
	String str(Object o) {
		if (o==null) return "";
		return o.toString();
	}

	long timer = System.currentTimeMillis();
	void startTimer() {
		timer = System.currentTimeMillis();
	}
	void stopTimer() {
		System.err.println("time: "+(System.currentTimeMillis()-timer)/1000.0);
	}

	static class InputReader {
		private byte[] buf;
		private int bufPos = 0, bufLim = -1;
		private InputStream stream;
		public InputReader(InputStream stream, int size) {
			buf = new byte[size];
			this.stream = stream;
		}
		private void fillBuf() throws IOException {
			bufLim = stream.read(buf);
			bufPos = 0;
		}
		char read() throws IOException {
			if (bufPos>=bufLim) fillBuf();
			return (char)buf[bufPos++];
		}
		boolean hasInput() throws IOException {
			if (bufPos>=bufLim) fillBuf();
			return bufPos<bufLim;
		}
	}

	static InputReader inputReader;
	static BufferedWriter outputWriter;

	char nextChar() throws IOException {
		return inputReader.read();
	}
	char nextNonWhitespaceChar() throws IOException {
		char c = inputReader.read();
		while (c<=' ') c=inputReader.read();
		return c;
	}
	String nextWord() throws IOException {
		StringBuilder sb = new StringBuilder();
		char c = inputReader.read();
		while (c<=' ') c=inputReader.read();
		while (c>' ') {
			sb.append(c);
			c = inputReader.read();
		}
		return new String(sb);
	}
	String nextLine() throws IOException {
		StringBuilder sb = new StringBuilder();
		char c = inputReader.read();
		while (c<=' ') c=inputReader.read();
		while (c!='\n' && c!='\r') {
			sb.append(c);
			c = inputReader.read();
		}
		return new String(sb);
	}
	int nextInt() throws IOException {
		int r = 0;
		char c = nextNonWhitespaceChar();
		boolean neg = false;
		if (c=='-') neg=true;
		else r=c-48;
		c = nextChar();
		while (c>='0' && c<='9') {
			r*=10;
			r+=c-48;
			c=nextChar();
		}
		return neg ? -r:r;
	}
	long nextLong() throws IOException {
		long r = 0;
		char c = nextNonWhitespaceChar();
		boolean neg = false;
		if (c=='-') neg=true;
		else r = c-48;
		c = nextChar();
		while (c>='0' && c<='9') {
			r*=10L;
			r+=c-48L;
			c=nextChar();
		}
		return neg ? -r:r;
	}
	double nextDouble() throws NumberFormatException, IOException {
		return Double.parseDouble(nextWord());
	}
	int[] nextArr(int size) throws NumberFormatException, IOException {
		int[] arr = new int[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextInt();
		return arr;
	}
	long[] nextArrL(int size) throws NumberFormatException, IOException {
		long[] arr = new long[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextLong();
		return arr;
	}
	double[] nextArrD(int size) throws NumberFormatException, IOException {
		double[] arr = new double[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextDouble();
		return arr;
	}
	String[] nextArrS(int size) throws NumberFormatException, IOException {
		String[] arr = new String[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextWord();
		return arr;
	}
	char[] nextArrCh(int size) throws IOException {
		char[] arr = new char[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextNonWhitespaceChar();
		return arr;
	}
	char[][] nextArrCh(int rows, int columns) throws IOException {
		char[][] arr = new char[rows][columns];
		for (int i=0; i<rows; ++i)
			for (int j=0; j<columns; ++j)
				arr[i][j] = nextNonWhitespaceChar();
		return arr;
	}
	char[][] nextArrChBorders(int rows, int columns, char border) throws IOException {
		char[][] arr = new char[rows+2][columns+2];
		for (int i=1; i<=rows; ++i)
			for (int j=1; j<=columns; ++j)
				arr[i][j] = nextNonWhitespaceChar();
		for (int i=0; i<columns+2; ++i) {
			arr[0][i] = border;
			arr[rows+1][i] = border;
		}
		for (int i=0; i<rows+2; ++i) {
			arr[i][0] = border;
			arr[i][columns+1] = border;
		}
		return arr;
	}

	void printf(String format, Object... args) throws IOException {
		outputWriter.write(String.format(format, args));
	}
	void print(Object o) throws IOException {
		outputWriter.write(o.toString());
	}
	void println(Object o) throws IOException {
		outputWriter.write(o.toString());
		outputWriter.newLine();
	}
	void print(Object... o) throws IOException {
		for (int i=0; i<o.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(o[i].toString());
		}
	}
	void println(Object... o) throws IOException {
		print(o);
		outputWriter.newLine();
	}
	void printn(Object o, int n) throws IOException {
		String s = o.toString();
		for (int i=0; i<n; ++i) {
			outputWriter.write(s);
			if (i!=n-1) outputWriter.write(' ');
		}
	}
	void printnln(Object o, int n) throws IOException {
		printn(o, n);
		outputWriter.newLine();
	}
	void printArr(int[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(Integer.toString(arr[i]));
		}
	}
	void printArr(long[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(Long.toString(arr[i]));
		}
	}
	void printArr(double[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(Double.toString(arr[i]));
		}
	}
	void printArr(String[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(arr[i]);
		}
	}
	void printlnArr(int[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void printlnArr(long[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void printlnArr(double[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void printlnArr(String[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void halt(Object... o) throws IOException {
		if (o.length!=0) println(o);
		outputWriter.flush(); outputWriter.close();
		System.exit(0);
	}

	void debug(Object... o) {
		if (showDebug) System.err.println(Arrays.deepToString(o));
	}

	public static void main(String[] args) throws Exception {
		Locale.setDefault(Locale.US);
		if (!useFiles) {
			inputReader = new InputReader(System.in, 1<<16);
			outputWriter = new BufferedWriter(new OutputStreamWriter(System.out), 1<<16);
		} else {
			inputReader = new InputReader(new FileInputStream(new File(inFile)), 1<<16);
			outputWriter = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(new File(outFile))), 1<<16);
		}
		new D().solve();
		outputWriter.flush(); outputWriter.close();
	}
}


import static java.lang.Math.*;
import java.util.*;
import java.io.*;

public class D {

	public void solve() throws Exception {

		int n = nextInt(), m = nextInt(), t = nextInt();
		int[] starts = new int[n];
		for (int i=0; i<n; ++i) {
			String[] s = nextLine().split(":");
			starts[i] = Integer.parseInt(s[0]) * 3600 + Integer.parseInt(s[1]) * 60 + Integer.parseInt(s[2]);
		}

		int max = 0;
		LinkedList<Integer> open = new LinkedList<Integer>();
		LinkedList<Integer> idsFree = new LinkedList<Integer>();
		LinkedList<Integer> idsTaken = new LinkedList<Integer>();
		for (int i=1; i<=n; ++i) idsFree.add(i);
		int idmax = 0;
		LinkedList<Integer> res = new LinkedList<Integer>();
		for (int start: starts) {
			while (!open.isEmpty() && open.peek() <= start) {
				open.poll();
				int idB = idsTaken.poll();
				idsFree.add(idB);
			}
			int id = 0;
			if (open.size() >= m) {
				id = idsTaken.getLast();
				open.remove(open.getLast());
			} else {
				id = idsFree.poll();
				idsTaken.add(id);
			}
			res.add(id);
			idmax = max(idmax, id);
			open.add(start+t);
			max = max(max, open.size());
		}

		if (max<m) {
			println("No solution");
		} else {
			println(idmax);
			for (int id: res) println(id);
		}

	}

	////////////////////////////////////////////////////////////////////////////

	boolean showDebug = true;
	static boolean useFiles = false;
	static String inFile = "input.txt";
	static String outFile = "output.txt";

	double EPS = 1e-7;
	int INF = Integer.MAX_VALUE;
	long INFL = Long.MAX_VALUE;
	double INFD = Double.MAX_VALUE;

	int absPos(int num) {
		return num<0 ? 0:num;
	}
	long absPos(long num) {
		return num<0 ? 0:num;
	}
	double absPos(double num) {
		return num<0 ? 0:num;
	}

	int min(int... nums) {
		int r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]<r) r=nums[i];
		return r;
	}
	int max(int... nums) {
		int r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]>r) r=nums[i];
		return r;
	}
	long minL(long... nums) {
		long r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]<r) r=nums[i];
		return r;
	}
	long maxL(long... nums) {
		long r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]>r) r=nums[i];
		return r;
	}
	double minD(double... nums) {
		double r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]<r) r=nums[i];
		return r;
	}
	double maxD(double... nums) {
		double r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]>r) r=nums[i];
		return r;
	}

	long sumArr(int[] arr) {
		long res = 0;
		for (int i=0; i<arr.length; ++i)
			res+=arr[i];
		return res;
	}
	long sumArr(long[] arr) {
		long res = 0;
		for (int i=0; i<arr.length; ++i)
			res+=arr[i];
		return res;
	}
	double sumArr(double[] arr) {
		double res = 0;
		for (int i=0; i<arr.length; ++i)
			res+=arr[i];
		return res;
	}

	long partsFitCnt(long partSize, long wholeSize) {
		return (partSize+wholeSize-1)/partSize;
	}

	boolean odd(long num) {
		return (num&1)==1;
	}

	boolean hasBit(int num, int pos) {
		return (num&(1<<pos))>0;
	}

	boolean isLetter(char c) {
		return (c>='a' && c<='z') || (c>='A' && c<='Z');
	}
	boolean isLowercase(char c) {
		return (c>='a' && c<='z');
	}
	boolean isUppercase(char c) {
		return (c>='A' && c<='Z');
	}
	boolean isDigit(char c) {
		return (c>='0' && c<='9');
	}

	boolean charIn(String chars, String s) {
		if (s==null) return false;
		if (chars==null || chars.equals("")) return true;
		for (int i=0; i<s.length(); ++i)
			for (int j=0; j<chars.length(); ++j)
				if (chars.charAt(j)==s.charAt(i)) return true;
		return false;
	}

	String stringn(String s, int n) {
		if (n<1 || s==null) return "";
		StringBuilder sb = new StringBuilder(s.length()*n);
		for (int i=0; i<n; ++i) sb.append(s);
		return sb.toString();
	}
	String str(Object o) {
		if (o==null) return "";
		return o.toString();
	}

	long timer = System.currentTimeMillis();
	void startTimer() {
		timer = System.currentTimeMillis();
	}
	void stopTimer() {
		System.err.println("time: "+(System.currentTimeMillis()-timer)/1000.0);
	}

	static class InputReader {
		private byte[] buf;
		private int bufPos = 0, bufLim = -1;
		private InputStream stream;
		public InputReader(InputStream stream, int size) {
			buf = new byte[size];
			this.stream = stream;
		}
		private void fillBuf() throws IOException {
			bufLim = stream.read(buf);
			bufPos = 0;
		}
		char read() throws IOException {
			if (bufPos>=bufLim) fillBuf();
			return (char)buf[bufPos++];
		}
		boolean hasInput() throws IOException {
			if (bufPos>=bufLim) fillBuf();
			return bufPos<bufLim;
		}
	}

	static InputReader inputReader;
	static BufferedWriter outputWriter;

	char nextChar() throws IOException {
		return inputReader.read();
	}
	char nextNonWhitespaceChar() throws IOException {
		char c = inputReader.read();
		while (c<=' ') c=inputReader.read();
		return c;
	}
	String nextWord() throws IOException {
		StringBuilder sb = new StringBuilder();
		char c = inputReader.read();
		while (c<=' ') c=inputReader.read();
		while (c>' ') {
			sb.append(c);
			c = inputReader.read();
		}
		return new String(sb);
	}
	String nextLine() throws IOException {
		StringBuilder sb = new StringBuilder();
		char c = inputReader.read();
		while (c<=' ') c=inputReader.read();
		while (c!='\n' && c!='\r') {
			sb.append(c);
			c = inputReader.read();
		}
		return new String(sb);
	}
	int nextInt() throws IOException {
		int r = 0;
		char c = nextNonWhitespaceChar();
		boolean neg = false;
		if (c=='-') neg=true;
		else r=c-48;
		c = nextChar();
		while (c>='0' && c<='9') {
			r*=10;
			r+=c-48;
			c=nextChar();
		}
		return neg ? -r:r;
	}
	long nextLong() throws IOException {
		long r = 0;
		char c = nextNonWhitespaceChar();
		boolean neg = false;
		if (c=='-') neg=true;
		else r = c-48;
		c = nextChar();
		while (c>='0' && c<='9') {
			r*=10L;
			r+=c-48L;
			c=nextChar();
		}
		return neg ? -r:r;
	}
	double nextDouble() throws NumberFormatException, IOException {
		return Double.parseDouble(nextWord());
	}
	int[] nextArr(int size) throws NumberFormatException, IOException {
		int[] arr = new int[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextInt();
		return arr;
	}
	long[] nextArrL(int size) throws NumberFormatException, IOException {
		long[] arr = new long[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextLong();
		return arr;
	}
	double[] nextArrD(int size) throws NumberFormatException, IOException {
		double[] arr = new double[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextDouble();
		return arr;
	}
	String[] nextArrS(int size) throws NumberFormatException, IOException {
		String[] arr = new String[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextWord();
		return arr;
	}
	char[] nextArrCh(int size) throws IOException {
		char[] arr = new char[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextNonWhitespaceChar();
		return arr;
	}
	char[][] nextArrCh(int rows, int columns) throws IOException {
		char[][] arr = new char[rows][columns];
		for (int i=0; i<rows; ++i)
			for (int j=0; j<columns; ++j)
				arr[i][j] = nextNonWhitespaceChar();
		return arr;
	}
	char[][] nextArrChBorders(int rows, int columns, char border) throws IOException {
		char[][] arr = new char[rows+2][columns+2];
		for (int i=1; i<=rows; ++i)
			for (int j=1; j<=columns; ++j)
				arr[i][j] = nextNonWhitespaceChar();
		for (int i=0; i<columns+2; ++i) {
			arr[0][i] = border;
			arr[rows+1][i] = border;
		}
		for (int i=0; i<rows+2; ++i) {
			arr[i][0] = border;
			arr[i][columns+1] = border;
		}
		return arr;
	}

	void printf(String format, Object... args) throws IOException {
		outputWriter.write(String.format(format, args));
	}
	void print(Object o) throws IOException {
		outputWriter.write(o.toString());
	}
	void println(Object o) throws IOException {
		outputWriter.write(o.toString());
		outputWriter.newLine();
	}
	void print(Object... o) throws IOException {
		for (int i=0; i<o.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(o[i].toString());
		}
	}
	void println(Object... o) throws IOException {
		print(o);
		outputWriter.newLine();
	}
	void printn(Object o, int n) throws IOException {
		String s = o.toString();
		for (int i=0; i<n; ++i) {
			outputWriter.write(s);
			if (i!=n-1) outputWriter.write(' ');
		}
	}
	void printnln(Object o, int n) throws IOException {
		printn(o, n);
		outputWriter.newLine();
	}
	void printArr(int[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(Integer.toString(arr[i]));
		}
	}
	void printArr(long[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(Long.toString(arr[i]));
		}
	}
	void printArr(double[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(Double.toString(arr[i]));
		}
	}
	void printArr(String[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(arr[i]);
		}
	}
	void printlnArr(int[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void printlnArr(long[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void printlnArr(double[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void printlnArr(String[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void halt(Object... o) throws IOException {
		if (o.length!=0) println(o);
		outputWriter.flush(); outputWriter.close();
		System.exit(0);
	}

	void debug(Object... o) {
		if (showDebug) System.err.println(Arrays.deepToString(o));
	}

	public static void main(String[] args) throws Exception {
		Locale.setDefault(Locale.US);
		if (!useFiles) {
			inputReader = new InputReader(System.in, 1<<16);
			outputWriter = new BufferedWriter(new OutputStreamWriter(System.out), 1<<16);
		} else {
			inputReader = new InputReader(new FileInputStream(new File(inFile)), 1<<16);
			outputWriter = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(new File(outFile))), 1<<16);
		}
		new D().solve();
		outputWriter.flush(); outputWriter.close();
	}
}


import static java.lang.Math.*;
import java.util.*;
import java.io.*;

public class D {

	public void solve() throws Exception {

		int n = nextInt(), m = nextInt(), t = nextInt();
		ArrayList<Integer> starts = new ArrayList<Integer>();
		int max = 0;
		for (int i=0; i<n; ++i) {
			String[] s = nextLine().split(":");
			int tcurr = Integer.parseInt(s[0]) * 3600 + Integer.parseInt(s[1]) * 60 + Integer.parseInt(s[2]);
			starts.add(tcurr);
		}

		LinkedList<Integer> open = new LinkedList<Integer>();
		for (int start: starts) {
			int end = start+t;
			open.add(end);
			while (!open.isEmpty() && open.peek() <= start) {
				open.poll();
			}
			max = max(max, open.size());
		}

		if (max<m) {
			println("No solution");
			return;
		}

		open = new LinkedList<Integer>();
		LinkedList<Integer> idsFree = new LinkedList<Integer>();
		LinkedList<Integer> idsTaken = new LinkedList<Integer>();
		for (int i=1; i<=n; ++i) idsFree.add(i);
		int idmax = 0;
		LinkedList<Integer> res = new LinkedList<Integer>();
		for (int start: starts) {
			while (!open.isEmpty() && open.peek() <= start) {
				open.poll();
				int idB = idsTaken.poll();
				idsFree.add(idB);
			}
			int id = 0;
			if (open.size() >= m) {
				id = idsTaken.getLast();
				open.remove(open.getLast());
			} else {
				id = idsFree.poll();
				idsTaken.add(id);
			}
			res.add(id);
			idmax = max(idmax, id);
			open.add(start+t);
		}

		println(idmax);
		for (int id: res) println(id);

	}

	////////////////////////////////////////////////////////////////////////////

	boolean showDebug = true;
	static boolean useFiles = false;
	static String inFile = "input.txt";
	static String outFile = "output.txt";

	double EPS = 1e-7;
	int INF = Integer.MAX_VALUE;
	long INFL = Long.MAX_VALUE;
	double INFD = Double.MAX_VALUE;

	int absPos(int num) {
		return num<0 ? 0:num;
	}
	long absPos(long num) {
		return num<0 ? 0:num;
	}
	double absPos(double num) {
		return num<0 ? 0:num;
	}

	int min(int... nums) {
		int r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]<r) r=nums[i];
		return r;
	}
	int max(int... nums) {
		int r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]>r) r=nums[i];
		return r;
	}
	long minL(long... nums) {
		long r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]<r) r=nums[i];
		return r;
	}
	long maxL(long... nums) {
		long r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]>r) r=nums[i];
		return r;
	}
	double minD(double... nums) {
		double r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]<r) r=nums[i];
		return r;
	}
	double maxD(double... nums) {
		double r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]>r) r=nums[i];
		return r;
	}

	long sumArr(int[] arr) {
		long res = 0;
		for (int i=0; i<arr.length; ++i)
			res+=arr[i];
		return res;
	}
	long sumArr(long[] arr) {
		long res = 0;
		for (int i=0; i<arr.length; ++i)
			res+=arr[i];
		return res;
	}
	double sumArr(double[] arr) {
		double res = 0;
		for (int i=0; i<arr.length; ++i)
			res+=arr[i];
		return res;
	}

	long partsFitCnt(long partSize, long wholeSize) {
		return (partSize+wholeSize-1)/partSize;
	}

	boolean odd(long num) {
		return (num&1)==1;
	}

	boolean hasBit(int num, int pos) {
		return (num&(1<<pos))>0;
	}

	boolean isLetter(char c) {
		return (c>='a' && c<='z') || (c>='A' && c<='Z');
	}
	boolean isLowercase(char c) {
		return (c>='a' && c<='z');
	}
	boolean isUppercase(char c) {
		return (c>='A' && c<='Z');
	}
	boolean isDigit(char c) {
		return (c>='0' && c<='9');
	}

	boolean charIn(String chars, String s) {
		if (s==null) return false;
		if (chars==null || chars.equals("")) return true;
		for (int i=0; i<s.length(); ++i)
			for (int j=0; j<chars.length(); ++j)
				if (chars.charAt(j)==s.charAt(i)) return true;
		return false;
	}

	String stringn(String s, int n) {
		if (n<1 || s==null) return "";
		StringBuilder sb = new StringBuilder(s.length()*n);
		for (int i=0; i<n; ++i) sb.append(s);
		return sb.toString();
	}
	String str(Object o) {
		if (o==null) return "";
		return o.toString();
	}

	long timer = System.currentTimeMillis();
	void startTimer() {
		timer = System.currentTimeMillis();
	}
	void stopTimer() {
		System.err.println("time: "+(System.currentTimeMillis()-timer)/1000.0);
	}

	static class InputReader {
		private byte[] buf;
		private int bufPos = 0, bufLim = -1;
		private InputStream stream;
		public InputReader(InputStream stream, int size) {
			buf = new byte[size];
			this.stream = stream;
		}
		private void fillBuf() throws IOException {
			bufLim = stream.read(buf);
			bufPos = 0;
		}
		char read() throws IOException {
			if (bufPos>=bufLim) fillBuf();
			return (char)buf[bufPos++];
		}
		boolean hasInput() throws IOException {
			if (bufPos>=bufLim) fillBuf();
			return bufPos<bufLim;
		}
	}

	static InputReader inputReader;
	static BufferedWriter outputWriter;

	char nextChar() throws IOException {
		return inputReader.read();
	}
	char nextNonWhitespaceChar() throws IOException {
		char c = inputReader.read();
		while (c<=' ') c=inputReader.read();
		return c;
	}
	String nextWord() throws IOException {
		StringBuilder sb = new StringBuilder();
		char c = inputReader.read();
		while (c<=' ') c=inputReader.read();
		while (c>' ') {
			sb.append(c);
			c = inputReader.read();
		}
		return new String(sb);
	}
	String nextLine() throws IOException {
		StringBuilder sb = new StringBuilder();
		char c = inputReader.read();
		while (c<=' ') c=inputReader.read();
		while (c!='\n' && c!='\r') {
			sb.append(c);
			c = inputReader.read();
		}
		return new String(sb);
	}
	int nextInt() throws IOException {
		int r = 0;
		char c = nextNonWhitespaceChar();
		boolean neg = false;
		if (c=='-') neg=true;
		else r=c-48;
		c = nextChar();
		while (c>='0' && c<='9') {
			r*=10;
			r+=c-48;
			c=nextChar();
		}
		return neg ? -r:r;
	}
	long nextLong() throws IOException {
		long r = 0;
		char c = nextNonWhitespaceChar();
		boolean neg = false;
		if (c=='-') neg=true;
		else r = c-48;
		c = nextChar();
		while (c>='0' && c<='9') {
			r*=10L;
			r+=c-48L;
			c=nextChar();
		}
		return neg ? -r:r;
	}
	double nextDouble() throws NumberFormatException, IOException {
		return Double.parseDouble(nextWord());
	}
	int[] nextArr(int size) throws NumberFormatException, IOException {
		int[] arr = new int[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextInt();
		return arr;
	}
	long[] nextArrL(int size) throws NumberFormatException, IOException {
		long[] arr = new long[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextLong();
		return arr;
	}
	double[] nextArrD(int size) throws NumberFormatException, IOException {
		double[] arr = new double[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextDouble();
		return arr;
	}
	String[] nextArrS(int size) throws NumberFormatException, IOException {
		String[] arr = new String[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextWord();
		return arr;
	}
	char[] nextArrCh(int size) throws IOException {
		char[] arr = new char[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextNonWhitespaceChar();
		return arr;
	}
	char[][] nextArrCh(int rows, int columns) throws IOException {
		char[][] arr = new char[rows][columns];
		for (int i=0; i<rows; ++i)
			for (int j=0; j<columns; ++j)
				arr[i][j] = nextNonWhitespaceChar();
		return arr;
	}
	char[][] nextArrChBorders(int rows, int columns, char border) throws IOException {
		char[][] arr = new char[rows+2][columns+2];
		for (int i=1; i<=rows; ++i)
			for (int j=1; j<=columns; ++j)
				arr[i][j] = nextNonWhitespaceChar();
		for (int i=0; i<columns+2; ++i) {
			arr[0][i] = border;
			arr[rows+1][i] = border;
		}
		for (int i=0; i<rows+2; ++i) {
			arr[i][0] = border;
			arr[i][columns+1] = border;
		}
		return arr;
	}

	void printf(String format, Object... args) throws IOException {
		outputWriter.write(String.format(format, args));
	}
	void print(Object o) throws IOException {
		outputWriter.write(o.toString());
	}
	void println(Object o) throws IOException {
		outputWriter.write(o.toString());
		outputWriter.newLine();
	}
	void print(Object... o) throws IOException {
		for (int i=0; i<o.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(o[i].toString());
		}
	}
	void println(Object... o) throws IOException {
		print(o);
		outputWriter.newLine();
	}
	void printn(Object o, int n) throws IOException {
		String s = o.toString();
		for (int i=0; i<n; ++i) {
			outputWriter.write(s);
			if (i!=n-1) outputWriter.write(' ');
		}
	}
	void printnln(Object o, int n) throws IOException {
		printn(o, n);
		outputWriter.newLine();
	}
	void printArr(int[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(Integer.toString(arr[i]));
		}
	}
	void printArr(long[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(Long.toString(arr[i]));
		}
	}
	void printArr(double[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(Double.toString(arr[i]));
		}
	}
	void printArr(String[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(arr[i]);
		}
	}
	void printlnArr(int[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void printlnArr(long[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void printlnArr(double[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void printlnArr(String[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void halt(Object... o) throws IOException {
		if (o.length!=0) println(o);
		outputWriter.flush(); outputWriter.close();
		System.exit(0);
	}

	void debug(Object... o) {
		if (showDebug) System.err.println(Arrays.deepToString(o));
	}

	public static void main(String[] args) throws Exception {
		Locale.setDefault(Locale.US);
		if (!useFiles) {
			inputReader = new InputReader(System.in, 1<<16);
			outputWriter = new BufferedWriter(new OutputStreamWriter(System.out), 1<<16);
		} else {
			inputReader = new InputReader(new FileInputStream(new File(inFile)), 1<<16);
			outputWriter = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(new File(outFile))), 1<<16);
		}
		new D().solve();
		outputWriter.flush(); outputWriter.close();
	}
}


import static java.lang.Math.*;
import java.util.*;
import java.io.*;

public class D {

	public void solve() throws Exception {

		int n = nextInt(), m = nextInt(), t = nextInt();
		ArrayList<Integer> starts = new ArrayList<Integer>();
		int max = 0;
		for (int i=0; i<n; ++i) {
			String[] s = nextLine().split(":");
			int tcurr = Integer.parseInt(s[0]) * 24 * 60 + Integer.parseInt(s[1]) * 60 + Integer.parseInt(s[2]);
			starts.add(tcurr);
		}

		LinkedList<Integer> open = new LinkedList<Integer>();
		for (int start: starts) {
			int end = start+t;
			open.add(end);
			while (!open.isEmpty() && open.peek() <= start) {
				open.poll();
			}
			max = max(max, open.size());
		}

		if (max<m) {
			println("No solution");
			return;
		}

		println(max);

		open = new LinkedList<Integer>();
		LinkedList<Integer> idsFree = new LinkedList<Integer>();
		LinkedList<Integer> idsTaken = new LinkedList<Integer>();
		for (int i=1; i<=max; ++i) idsFree.add(i);
		for (int start: starts) {
			while (!open.isEmpty() && open.peek() <= start) {
				open.poll();
				int idB = idsTaken.poll();
				idsFree.add(idB);
			}
			if (open.size() >= m) {
				open.remove(open.getLast());
				println(idsTaken.getLast());
			} else {
				int id = idsFree.poll();
				idsTaken.add(id);
				println(id);
			}
			open.add(start+t);
		}

	}

	////////////////////////////////////////////////////////////////////////////

	boolean showDebug = true;
	static boolean useFiles = false;
	static String inFile = "input.txt";
	static String outFile = "output.txt";

	double EPS = 1e-7;
	int INF = Integer.MAX_VALUE;
	long INFL = Long.MAX_VALUE;
	double INFD = Double.MAX_VALUE;

	int absPos(int num) {
		return num<0 ? 0:num;
	}
	long absPos(long num) {
		return num<0 ? 0:num;
	}
	double absPos(double num) {
		return num<0 ? 0:num;
	}

	int min(int... nums) {
		int r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]<r) r=nums[i];
		return r;
	}
	int max(int... nums) {
		int r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]>r) r=nums[i];
		return r;
	}
	long minL(long... nums) {
		long r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]<r) r=nums[i];
		return r;
	}
	long maxL(long... nums) {
		long r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]>r) r=nums[i];
		return r;
	}
	double minD(double... nums) {
		double r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]<r) r=nums[i];
		return r;
	}
	double maxD(double... nums) {
		double r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]>r) r=nums[i];
		return r;
	}

	long sumArr(int[] arr) {
		long res = 0;
		for (int i=0; i<arr.length; ++i)
			res+=arr[i];
		return res;
	}
	long sumArr(long[] arr) {
		long res = 0;
		for (int i=0; i<arr.length; ++i)
			res+=arr[i];
		return res;
	}
	double sumArr(double[] arr) {
		double res = 0;
		for (int i=0; i<arr.length; ++i)
			res+=arr[i];
		return res;
	}

	long partsFitCnt(long partSize, long wholeSize) {
		return (partSize+wholeSize-1)/partSize;
	}

	boolean odd(long num) {
		return (num&1)==1;
	}

	boolean hasBit(int num, int pos) {
		return (num&(1<<pos))>0;
	}

	boolean isLetter(char c) {
		return (c>='a' && c<='z') || (c>='A' && c<='Z');
	}
	boolean isLowercase(char c) {
		return (c>='a' && c<='z');
	}
	boolean isUppercase(char c) {
		return (c>='A' && c<='Z');
	}
	boolean isDigit(char c) {
		return (c>='0' && c<='9');
	}

	boolean charIn(String chars, String s) {
		if (s==null) return false;
		if (chars==null || chars.equals("")) return true;
		for (int i=0; i<s.length(); ++i)
			for (int j=0; j<chars.length(); ++j)
				if (chars.charAt(j)==s.charAt(i)) return true;
		return false;
	}

	String stringn(String s, int n) {
		if (n<1 || s==null) return "";
		StringBuilder sb = new StringBuilder(s.length()*n);
		for (int i=0; i<n; ++i) sb.append(s);
		return sb.toString();
	}
	String str(Object o) {
		if (o==null) return "";
		return o.toString();
	}

	long timer = System.currentTimeMillis();
	void startTimer() {
		timer = System.currentTimeMillis();
	}
	void stopTimer() {
		System.err.println("time: "+(System.currentTimeMillis()-timer)/1000.0);
	}

	static class InputReader {
		private byte[] buf;
		private int bufPos = 0, bufLim = -1;
		private InputStream stream;
		public InputReader(InputStream stream, int size) {
			buf = new byte[size];
			this.stream = stream;
		}
		private void fillBuf() throws IOException {
			bufLim = stream.read(buf);
			bufPos = 0;
		}
		char read() throws IOException {
			if (bufPos>=bufLim) fillBuf();
			return (char)buf[bufPos++];
		}
		boolean hasInput() throws IOException {
			if (bufPos>=bufLim) fillBuf();
			return bufPos<bufLim;
		}
	}

	static InputReader inputReader;
	static BufferedWriter outputWriter;

	char nextChar() throws IOException {
		return inputReader.read();
	}
	char nextNonWhitespaceChar() throws IOException {
		char c = inputReader.read();
		while (c<=' ') c=inputReader.read();
		return c;
	}
	String nextWord() throws IOException {
		StringBuilder sb = new StringBuilder();
		char c = inputReader.read();
		while (c<=' ') c=inputReader.read();
		while (c>' ') {
			sb.append(c);
			c = inputReader.read();
		}
		return new String(sb);
	}
	String nextLine() throws IOException {
		StringBuilder sb = new StringBuilder();
		char c = inputReader.read();
		while (c<=' ') c=inputReader.read();
		while (c!='\n' && c!='\r') {
			sb.append(c);
			c = inputReader.read();
		}
		return new String(sb);
	}
	int nextInt() throws IOException {
		int r = 0;
		char c = nextNonWhitespaceChar();
		boolean neg = false;
		if (c=='-') neg=true;
		else r=c-48;
		c = nextChar();
		while (c>='0' && c<='9') {
			r*=10;
			r+=c-48;
			c=nextChar();
		}
		return neg ? -r:r;
	}
	long nextLong() throws IOException {
		long r = 0;
		char c = nextNonWhitespaceChar();
		boolean neg = false;
		if (c=='-') neg=true;
		else r = c-48;
		c = nextChar();
		while (c>='0' && c<='9') {
			r*=10L;
			r+=c-48L;
			c=nextChar();
		}
		return neg ? -r:r;
	}
	double nextDouble() throws NumberFormatException, IOException {
		return Double.parseDouble(nextWord());
	}
	int[] nextArr(int size) throws NumberFormatException, IOException {
		int[] arr = new int[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextInt();
		return arr;
	}
	long[] nextArrL(int size) throws NumberFormatException, IOException {
		long[] arr = new long[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextLong();
		return arr;
	}
	double[] nextArrD(int size) throws NumberFormatException, IOException {
		double[] arr = new double[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextDouble();
		return arr;
	}
	String[] nextArrS(int size) throws NumberFormatException, IOException {
		String[] arr = new String[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextWord();
		return arr;
	}
	char[] nextArrCh(int size) throws IOException {
		char[] arr = new char[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextNonWhitespaceChar();
		return arr;
	}
	char[][] nextArrCh(int rows, int columns) throws IOException {
		char[][] arr = new char[rows][columns];
		for (int i=0; i<rows; ++i)
			for (int j=0; j<columns; ++j)
				arr[i][j] = nextNonWhitespaceChar();
		return arr;
	}
	char[][] nextArrChBorders(int rows, int columns, char border) throws IOException {
		char[][] arr = new char[rows+2][columns+2];
		for (int i=1; i<=rows; ++i)
			for (int j=1; j<=columns; ++j)
				arr[i][j] = nextNonWhitespaceChar();
		for (int i=0; i<columns+2; ++i) {
			arr[0][i] = border;
			arr[rows+1][i] = border;
		}
		for (int i=0; i<rows+2; ++i) {
			arr[i][0] = border;
			arr[i][columns+1] = border;
		}
		return arr;
	}

	void printf(String format, Object... args) throws IOException {
		outputWriter.write(String.format(format, args));
	}
	void print(Object o) throws IOException {
		outputWriter.write(o.toString());
	}
	void println(Object o) throws IOException {
		outputWriter.write(o.toString());
		outputWriter.newLine();
	}
	void print(Object... o) throws IOException {
		for (int i=0; i<o.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(o[i].toString());
		}
	}
	void println(Object... o) throws IOException {
		print(o);
		outputWriter.newLine();
	}
	void printn(Object o, int n) throws IOException {
		String s = o.toString();
		for (int i=0; i<n; ++i) {
			outputWriter.write(s);
			if (i!=n-1) outputWriter.write(' ');
		}
	}
	void printnln(Object o, int n) throws IOException {
		printn(o, n);
		outputWriter.newLine();
	}
	void printArr(int[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(Integer.toString(arr[i]));
		}
	}
	void printArr(long[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(Long.toString(arr[i]));
		}
	}
	void printArr(double[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(Double.toString(arr[i]));
		}
	}
	void printArr(String[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(arr[i]);
		}
	}
	void printlnArr(int[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void printlnArr(long[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void printlnArr(double[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void printlnArr(String[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void halt(Object... o) throws IOException {
		if (o.length!=0) println(o);
		outputWriter.flush(); outputWriter.close();
		System.exit(0);
	}

	void debug(Object... o) {
		if (showDebug) System.err.println(Arrays.deepToString(o));
	}

	public static void main(String[] args) throws Exception {
		Locale.setDefault(Locale.US);
		if (!useFiles) {
			inputReader = new InputReader(System.in, 1<<16);
			outputWriter = new BufferedWriter(new OutputStreamWriter(System.out), 1<<16);
		} else {
			inputReader = new InputReader(new FileInputStream(new File(inFile)), 1<<16);
			outputWriter = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(new File(outFile))), 1<<16);
		}
		new D().solve();
		outputWriter.flush(); outputWriter.close();
	}
}


import static java.lang.Math.*;
import java.util.*;
import java.io.*;

public class D {

	public void solve() throws Exception {

		int n = nextInt(), m = nextInt(), t = nextInt();
		ArrayList<Integer> starts = new ArrayList<Integer>();
		int max = 0;
		for (int i=0; i<n; ++i) {
			String[] s = nextLine().split(":");
			int tcurr = Integer.parseInt(s[0]) * 24 * 60 + Integer.parseInt(s[1]) * 60 + Integer.parseInt(s[2]);
			starts.add(tcurr);
		}

		LinkedList<Integer> open = new LinkedList<Integer>();
		for (int start: starts) {
			int end = start+t;
			open.add(end);
			while (!open.isEmpty() && open.peek() <= start) {
				open.poll();
			}
			max = max(max, open.size());
		}

		if (max<m) {
			println("No solution");
			return;
		}

		open = new LinkedList<Integer>();
		LinkedList<Integer> idsFree = new LinkedList<Integer>();
		LinkedList<Integer> idsTaken = new LinkedList<Integer>();
		for (int i=1; i<=max; ++i) idsFree.add(i);
		int idmax = 0;
		LinkedList<Integer> res = new LinkedList<Integer>();
		for (int start: starts) {
			while (!open.isEmpty() && open.peek() <= start) {
				open.poll();
				int idB = idsTaken.poll();
				idsFree.add(idB);
			}
			int id = 0;
			if (open.size() >= m) {
				id = idsTaken.getLast();
				open.remove(open.getLast());
			} else {
				id = idsFree.poll();
				idsTaken.add(id);
			}
			res.add(id);
			idmax = max(idmax, id);
			open.add(start+t);
		}

		println(idmax);
		for (int id: res) println(id);

	}

	////////////////////////////////////////////////////////////////////////////

	boolean showDebug = true;
	static boolean useFiles = false;
	static String inFile = "input.txt";
	static String outFile = "output.txt";

	double EPS = 1e-7;
	int INF = Integer.MAX_VALUE;
	long INFL = Long.MAX_VALUE;
	double INFD = Double.MAX_VALUE;

	int absPos(int num) {
		return num<0 ? 0:num;
	}
	long absPos(long num) {
		return num<0 ? 0:num;
	}
	double absPos(double num) {
		return num<0 ? 0:num;
	}

	int min(int... nums) {
		int r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]<r) r=nums[i];
		return r;
	}
	int max(int... nums) {
		int r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]>r) r=nums[i];
		return r;
	}
	long minL(long... nums) {
		long r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]<r) r=nums[i];
		return r;
	}
	long maxL(long... nums) {
		long r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]>r) r=nums[i];
		return r;
	}
	double minD(double... nums) {
		double r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]<r) r=nums[i];
		return r;
	}
	double maxD(double... nums) {
		double r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]>r) r=nums[i];
		return r;
	}

	long sumArr(int[] arr) {
		long res = 0;
		for (int i=0; i<arr.length; ++i)
			res+=arr[i];
		return res;
	}
	long sumArr(long[] arr) {
		long res = 0;
		for (int i=0; i<arr.length; ++i)
			res+=arr[i];
		return res;
	}
	double sumArr(double[] arr) {
		double res = 0;
		for (int i=0; i<arr.length; ++i)
			res+=arr[i];
		return res;
	}

	long partsFitCnt(long partSize, long wholeSize) {
		return (partSize+wholeSize-1)/partSize;
	}

	boolean odd(long num) {
		return (num&1)==1;
	}

	boolean hasBit(int num, int pos) {
		return (num&(1<<pos))>0;
	}

	boolean isLetter(char c) {
		return (c>='a' && c<='z') || (c>='A' && c<='Z');
	}
	boolean isLowercase(char c) {
		return (c>='a' && c<='z');
	}
	boolean isUppercase(char c) {
		return (c>='A' && c<='Z');
	}
	boolean isDigit(char c) {
		return (c>='0' && c<='9');
	}

	boolean charIn(String chars, String s) {
		if (s==null) return false;
		if (chars==null || chars.equals("")) return true;
		for (int i=0; i<s.length(); ++i)
			for (int j=0; j<chars.length(); ++j)
				if (chars.charAt(j)==s.charAt(i)) return true;
		return false;
	}

	String stringn(String s, int n) {
		if (n<1 || s==null) return "";
		StringBuilder sb = new StringBuilder(s.length()*n);
		for (int i=0; i<n; ++i) sb.append(s);
		return sb.toString();
	}
	String str(Object o) {
		if (o==null) return "";
		return o.toString();
	}

	long timer = System.currentTimeMillis();
	void startTimer() {
		timer = System.currentTimeMillis();
	}
	void stopTimer() {
		System.err.println("time: "+(System.currentTimeMillis()-timer)/1000.0);
	}

	static class InputReader {
		private byte[] buf;
		private int bufPos = 0, bufLim = -1;
		private InputStream stream;
		public InputReader(InputStream stream, int size) {
			buf = new byte[size];
			this.stream = stream;
		}
		private void fillBuf() throws IOException {
			bufLim = stream.read(buf);
			bufPos = 0;
		}
		char read() throws IOException {
			if (bufPos>=bufLim) fillBuf();
			return (char)buf[bufPos++];
		}
		boolean hasInput() throws IOException {
			if (bufPos>=bufLim) fillBuf();
			return bufPos<bufLim;
		}
	}

	static InputReader inputReader;
	static BufferedWriter outputWriter;

	char nextChar() throws IOException {
		return inputReader.read();
	}
	char nextNonWhitespaceChar() throws IOException {
		char c = inputReader.read();
		while (c<=' ') c=inputReader.read();
		return c;
	}
	String nextWord() throws IOException {
		StringBuilder sb = new StringBuilder();
		char c = inputReader.read();
		while (c<=' ') c=inputReader.read();
		while (c>' ') {
			sb.append(c);
			c = inputReader.read();
		}
		return new String(sb);
	}
	String nextLine() throws IOException {
		StringBuilder sb = new StringBuilder();
		char c = inputReader.read();
		while (c<=' ') c=inputReader.read();
		while (c!='\n' && c!='\r') {
			sb.append(c);
			c = inputReader.read();
		}
		return new String(sb);
	}
	int nextInt() throws IOException {
		int r = 0;
		char c = nextNonWhitespaceChar();
		boolean neg = false;
		if (c=='-') neg=true;
		else r=c-48;
		c = nextChar();
		while (c>='0' && c<='9') {
			r*=10;
			r+=c-48;
			c=nextChar();
		}
		return neg ? -r:r;
	}
	long nextLong() throws IOException {
		long r = 0;
		char c = nextNonWhitespaceChar();
		boolean neg = false;
		if (c=='-') neg=true;
		else r = c-48;
		c = nextChar();
		while (c>='0' && c<='9') {
			r*=10L;
			r+=c-48L;
			c=nextChar();
		}
		return neg ? -r:r;
	}
	double nextDouble() throws NumberFormatException, IOException {
		return Double.parseDouble(nextWord());
	}
	int[] nextArr(int size) throws NumberFormatException, IOException {
		int[] arr = new int[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextInt();
		return arr;
	}
	long[] nextArrL(int size) throws NumberFormatException, IOException {
		long[] arr = new long[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextLong();
		return arr;
	}
	double[] nextArrD(int size) throws NumberFormatException, IOException {
		double[] arr = new double[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextDouble();
		return arr;
	}
	String[] nextArrS(int size) throws NumberFormatException, IOException {
		String[] arr = new String[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextWord();
		return arr;
	}
	char[] nextArrCh(int size) throws IOException {
		char[] arr = new char[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextNonWhitespaceChar();
		return arr;
	}
	char[][] nextArrCh(int rows, int columns) throws IOException {
		char[][] arr = new char[rows][columns];
		for (int i=0; i<rows; ++i)
			for (int j=0; j<columns; ++j)
				arr[i][j] = nextNonWhitespaceChar();
		return arr;
	}
	char[][] nextArrChBorders(int rows, int columns, char border) throws IOException {
		char[][] arr = new char[rows+2][columns+2];
		for (int i=1; i<=rows; ++i)
			for (int j=1; j<=columns; ++j)
				arr[i][j] = nextNonWhitespaceChar();
		for (int i=0; i<columns+2; ++i) {
			arr[0][i] = border;
			arr[rows+1][i] = border;
		}
		for (int i=0; i<rows+2; ++i) {
			arr[i][0] = border;
			arr[i][columns+1] = border;
		}
		return arr;
	}

	void printf(String format, Object... args) throws IOException {
		outputWriter.write(String.format(format, args));
	}
	void print(Object o) throws IOException {
		outputWriter.write(o.toString());
	}
	void println(Object o) throws IOException {
		outputWriter.write(o.toString());
		outputWriter.newLine();
	}
	void print(Object... o) throws IOException {
		for (int i=0; i<o.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(o[i].toString());
		}
	}
	void println(Object... o) throws IOException {
		print(o);
		outputWriter.newLine();
	}
	void printn(Object o, int n) throws IOException {
		String s = o.toString();
		for (int i=0; i<n; ++i) {
			outputWriter.write(s);
			if (i!=n-1) outputWriter.write(' ');
		}
	}
	void printnln(Object o, int n) throws IOException {
		printn(o, n);
		outputWriter.newLine();
	}
	void printArr(int[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(Integer.toString(arr[i]));
		}
	}
	void printArr(long[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(Long.toString(arr[i]));
		}
	}
	void printArr(double[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(Double.toString(arr[i]));
		}
	}
	void printArr(String[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(arr[i]);
		}
	}
	void printlnArr(int[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void printlnArr(long[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void printlnArr(double[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void printlnArr(String[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void halt(Object... o) throws IOException {
		if (o.length!=0) println(o);
		outputWriter.flush(); outputWriter.close();
		System.exit(0);
	}

	void debug(Object... o) {
		if (showDebug) System.err.println(Arrays.deepToString(o));
	}

	public static void main(String[] args) throws Exception {
		Locale.setDefault(Locale.US);
		if (!useFiles) {
			inputReader = new InputReader(System.in, 1<<16);
			outputWriter = new BufferedWriter(new OutputStreamWriter(System.out), 1<<16);
		} else {
			inputReader = new InputReader(new FileInputStream(new File(inFile)), 1<<16);
			outputWriter = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(new File(outFile))), 1<<16);
		}
		new D().solve();
		outputWriter.flush(); outputWriter.close();
	}
}


import static java.lang.Math.*;
import java.util.*;
import java.io.*;

public class D {

	public void solve() throws Exception {

		int n = nextInt(), m = nextInt(), t = nextInt();
		LinkedList<Integer> open = new LinkedList<Integer>();
		LinkedList<Integer> idsFree = new LinkedList<Integer>();
		LinkedList<Integer> idsTaken = new LinkedList<Integer>();
		for (int i=1; i<=n; ++i) idsFree.add(i);
		int idmax = 0;
		LinkedList<Integer> res = new LinkedList<Integer>();
		for (int i=0; i<n; ++i) {
			String[] s = nextLine().split(":");
			int start = Integer.parseInt(s[0]) * 3600 + Integer.parseInt(s[1]) * 60 + Integer.parseInt(s[2]);
			while (!open.isEmpty() && open.peek() <= start) {
				open.poll();
				int idB = idsTaken.poll();
				idsFree.addFirst(idB);
			}
			int id = 0;
			if (open.size() >= m) {
				id = idsTaken.getLast();
				open.remove(open.getLast());
			} else {
				id = idsFree.poll();
				idsTaken.add(id);
			}
			res.add(id);
			idmax = max(idmax, id);
			open.add(start+t);
		}

		if (idmax<m) {
			println("No solution");
		} else {
			println(idmax);
			for (int id: res) println(id);
		}

	}

	////////////////////////////////////////////////////////////////////////////

	boolean showDebug = true;
	static boolean useFiles = false;
	static String inFile = "input.txt";
	static String outFile = "output.txt";

	double EPS = 1e-7;
	int INF = Integer.MAX_VALUE;
	long INFL = Long.MAX_VALUE;
	double INFD = Double.MAX_VALUE;

	int absPos(int num) {
		return num<0 ? 0:num;
	}
	long absPos(long num) {
		return num<0 ? 0:num;
	}
	double absPos(double num) {
		return num<0 ? 0:num;
	}

	int min(int... nums) {
		int r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]<r) r=nums[i];
		return r;
	}
	int max(int... nums) {
		int r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]>r) r=nums[i];
		return r;
	}
	long minL(long... nums) {
		long r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]<r) r=nums[i];
		return r;
	}
	long maxL(long... nums) {
		long r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]>r) r=nums[i];
		return r;
	}
	double minD(double... nums) {
		double r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]<r) r=nums[i];
		return r;
	}
	double maxD(double... nums) {
		double r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]>r) r=nums[i];
		return r;
	}

	long sumArr(int[] arr) {
		long res = 0;
		for (int i=0; i<arr.length; ++i)
			res+=arr[i];
		return res;
	}
	long sumArr(long[] arr) {
		long res = 0;
		for (int i=0; i<arr.length; ++i)
			res+=arr[i];
		return res;
	}
	double sumArr(double[] arr) {
		double res = 0;
		for (int i=0; i<arr.length; ++i)
			res+=arr[i];
		return res;
	}

	long partsFitCnt(long partSize, long wholeSize) {
		return (partSize+wholeSize-1)/partSize;
	}

	boolean odd(long num) {
		return (num&1)==1;
	}

	boolean hasBit(int num, int pos) {
		return (num&(1<<pos))>0;
	}

	boolean isLetter(char c) {
		return (c>='a' && c<='z') || (c>='A' && c<='Z');
	}
	boolean isLowercase(char c) {
		return (c>='a' && c<='z');
	}
	boolean isUppercase(char c) {
		return (c>='A' && c<='Z');
	}
	boolean isDigit(char c) {
		return (c>='0' && c<='9');
	}

	boolean charIn(String chars, String s) {
		if (s==null) return false;
		if (chars==null || chars.equals("")) return true;
		for (int i=0; i<s.length(); ++i)
			for (int j=0; j<chars.length(); ++j)
				if (chars.charAt(j)==s.charAt(i)) return true;
		return false;
	}

	String stringn(String s, int n) {
		if (n<1 || s==null) return "";
		StringBuilder sb = new StringBuilder(s.length()*n);
		for (int i=0; i<n; ++i) sb.append(s);
		return sb.toString();
	}
	String str(Object o) {
		if (o==null) return "";
		return o.toString();
	}

	long timer = System.currentTimeMillis();
	void startTimer() {
		timer = System.currentTimeMillis();
	}
	void stopTimer() {
		System.err.println("time: "+(System.currentTimeMillis()-timer)/1000.0);
	}

	static class InputReader {
		private byte[] buf;
		private int bufPos = 0, bufLim = -1;
		private InputStream stream;
		public InputReader(InputStream stream, int size) {
			buf = new byte[size];
			this.stream = stream;
		}
		private void fillBuf() throws IOException {
			bufLim = stream.read(buf);
			bufPos = 0;
		}
		char read() throws IOException {
			if (bufPos>=bufLim) fillBuf();
			return (char)buf[bufPos++];
		}
		boolean hasInput() throws IOException {
			if (bufPos>=bufLim) fillBuf();
			return bufPos<bufLim;
		}
	}

	static InputReader inputReader;
	static BufferedWriter outputWriter;

	char nextChar() throws IOException {
		return inputReader.read();
	}
	char nextNonWhitespaceChar() throws IOException {
		char c = inputReader.read();
		while (c<=' ') c=inputReader.read();
		return c;
	}
	String nextWord() throws IOException {
		StringBuilder sb = new StringBuilder();
		char c = inputReader.read();
		while (c<=' ') c=inputReader.read();
		while (c>' ') {
			sb.append(c);
			c = inputReader.read();
		}
		return new String(sb);
	}
	String nextLine() throws IOException {
		StringBuilder sb = new StringBuilder();
		char c = inputReader.read();
		while (c<=' ') c=inputReader.read();
		while (c!='\n' && c!='\r') {
			sb.append(c);
			c = inputReader.read();
		}
		return new String(sb);
	}
	int nextInt() throws IOException {
		int r = 0;
		char c = nextNonWhitespaceChar();
		boolean neg = false;
		if (c=='-') neg=true;
		else r=c-48;
		c = nextChar();
		while (c>='0' && c<='9') {
			r*=10;
			r+=c-48;
			c=nextChar();
		}
		return neg ? -r:r;
	}
	long nextLong() throws IOException {
		long r = 0;
		char c = nextNonWhitespaceChar();
		boolean neg = false;
		if (c=='-') neg=true;
		else r = c-48;
		c = nextChar();
		while (c>='0' && c<='9') {
			r*=10L;
			r+=c-48L;
			c=nextChar();
		}
		return neg ? -r:r;
	}
	double nextDouble() throws NumberFormatException, IOException {
		return Double.parseDouble(nextWord());
	}
	int[] nextArr(int size) throws NumberFormatException, IOException {
		int[] arr = new int[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextInt();
		return arr;
	}
	long[] nextArrL(int size) throws NumberFormatException, IOException {
		long[] arr = new long[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextLong();
		return arr;
	}
	double[] nextArrD(int size) throws NumberFormatException, IOException {
		double[] arr = new double[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextDouble();
		return arr;
	}
	String[] nextArrS(int size) throws NumberFormatException, IOException {
		String[] arr = new String[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextWord();
		return arr;
	}
	char[] nextArrCh(int size) throws IOException {
		char[] arr = new char[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextNonWhitespaceChar();
		return arr;
	}
	char[][] nextArrCh(int rows, int columns) throws IOException {
		char[][] arr = new char[rows][columns];
		for (int i=0; i<rows; ++i)
			for (int j=0; j<columns; ++j)
				arr[i][j] = nextNonWhitespaceChar();
		return arr;
	}
	char[][] nextArrChBorders(int rows, int columns, char border) throws IOException {
		char[][] arr = new char[rows+2][columns+2];
		for (int i=1; i<=rows; ++i)
			for (int j=1; j<=columns; ++j)
				arr[i][j] = nextNonWhitespaceChar();
		for (int i=0; i<columns+2; ++i) {
			arr[0][i] = border;
			arr[rows+1][i] = border;
		}
		for (int i=0; i<rows+2; ++i) {
			arr[i][0] = border;
			arr[i][columns+1] = border;
		}
		return arr;
	}

	void printf(String format, Object... args) throws IOException {
		outputWriter.write(String.format(format, args));
	}
	void print(Object o) throws IOException {
		outputWriter.write(o.toString());
	}
	void println(Object o) throws IOException {
		outputWriter.write(o.toString());
		outputWriter.newLine();
	}
	void print(Object... o) throws IOException {
		for (int i=0; i<o.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(o[i].toString());
		}
	}
	void println(Object... o) throws IOException {
		print(o);
		outputWriter.newLine();
	}
	void printn(Object o, int n) throws IOException {
		String s = o.toString();
		for (int i=0; i<n; ++i) {
			outputWriter.write(s);
			if (i!=n-1) outputWriter.write(' ');
		}
	}
	void printnln(Object o, int n) throws IOException {
		printn(o, n);
		outputWriter.newLine();
	}
	void printArr(int[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(Integer.toString(arr[i]));
		}
	}
	void printArr(long[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(Long.toString(arr[i]));
		}
	}
	void printArr(double[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(Double.toString(arr[i]));
		}
	}
	void printArr(String[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(arr[i]);
		}
	}
	void printlnArr(int[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void printlnArr(long[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void printlnArr(double[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void printlnArr(String[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void halt(Object... o) throws IOException {
		if (o.length!=0) println(o);
		outputWriter.flush(); outputWriter.close();
		System.exit(0);
	}

	void debug(Object... o) {
		if (showDebug) System.err.println(Arrays.deepToString(o));
	}

	public static void main(String[] args) throws Exception {
		Locale.setDefault(Locale.US);
		if (!useFiles) {
			inputReader = new InputReader(System.in, 1<<16);
			outputWriter = new BufferedWriter(new OutputStreamWriter(System.out), 1<<16);
		} else {
			inputReader = new InputReader(new FileInputStream(new File(inFile)), 1<<16);
			outputWriter = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(new File(outFile))), 1<<16);
		}
		new D().solve();
		outputWriter.flush(); outputWriter.close();
	}
}


import static java.lang.Math.*;
import java.util.*;
import java.io.*;

public class D {

	public void solve() throws Exception {

		int n = nextInt(), m = nextInt(), t = nextInt();
		LinkedList<Integer> open = new LinkedList<Integer>();
		LinkedList<Integer> idsFree = new LinkedList<Integer>();
		LinkedList<Integer> idsTaken = new LinkedList<Integer>();
		for (int i=1; i<=n; ++i) idsFree.add(i);
		int idmax = 0;
		LinkedList<Integer> res = new LinkedList<Integer>();
		for (int i=0; i<n; ++i) {
			String[] s = nextLine().split(":");
			int start = Integer.parseInt(s[0]) * 3600 + Integer.parseInt(s[1]) * 60 + Integer.parseInt(s[2]);
			while (!open.isEmpty() && open.peek() <= start) {
				open.poll();
				int idB = idsTaken.poll();
				idsFree.add(idB);
			}
			int id = 0;
			if (open.size() >= m) {
				id = idsTaken.getLast();
				open.remove(open.getLast());
			} else {
				id = idsFree.poll();
				idsTaken.add(id);
			}
			res.add(id);
			idmax = max(idmax, id);
			open.add(start+t);
		}

		if (idmax<m) {
			println("No solution");
		} else {
			println(idmax);
			for (int id: res) println(id);
		}

	}

	////////////////////////////////////////////////////////////////////////////

	boolean showDebug = true;
	static boolean useFiles = false;
	static String inFile = "input.txt";
	static String outFile = "output.txt";

	double EPS = 1e-7;
	int INF = Integer.MAX_VALUE;
	long INFL = Long.MAX_VALUE;
	double INFD = Double.MAX_VALUE;

	int absPos(int num) {
		return num<0 ? 0:num;
	}
	long absPos(long num) {
		return num<0 ? 0:num;
	}
	double absPos(double num) {
		return num<0 ? 0:num;
	}

	int min(int... nums) {
		int r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]<r) r=nums[i];
		return r;
	}
	int max(int... nums) {
		int r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]>r) r=nums[i];
		return r;
	}
	long minL(long... nums) {
		long r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]<r) r=nums[i];
		return r;
	}
	long maxL(long... nums) {
		long r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]>r) r=nums[i];
		return r;
	}
	double minD(double... nums) {
		double r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]<r) r=nums[i];
		return r;
	}
	double maxD(double... nums) {
		double r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]>r) r=nums[i];
		return r;
	}

	long sumArr(int[] arr) {
		long res = 0;
		for (int i=0; i<arr.length; ++i)
			res+=arr[i];
		return res;
	}
	long sumArr(long[] arr) {
		long res = 0;
		for (int i=0; i<arr.length; ++i)
			res+=arr[i];
		return res;
	}
	double sumArr(double[] arr) {
		double res = 0;
		for (int i=0; i<arr.length; ++i)
			res+=arr[i];
		return res;
	}

	long partsFitCnt(long partSize, long wholeSize) {
		return (partSize+wholeSize-1)/partSize;
	}

	boolean odd(long num) {
		return (num&1)==1;
	}

	boolean hasBit(int num, int pos) {
		return (num&(1<<pos))>0;
	}

	boolean isLetter(char c) {
		return (c>='a' && c<='z') || (c>='A' && c<='Z');
	}
	boolean isLowercase(char c) {
		return (c>='a' && c<='z');
	}
	boolean isUppercase(char c) {
		return (c>='A' && c<='Z');
	}
	boolean isDigit(char c) {
		return (c>='0' && c<='9');
	}

	boolean charIn(String chars, String s) {
		if (s==null) return false;
		if (chars==null || chars.equals("")) return true;
		for (int i=0; i<s.length(); ++i)
			for (int j=0; j<chars.length(); ++j)
				if (chars.charAt(j)==s.charAt(i)) return true;
		return false;
	}

	String stringn(String s, int n) {
		if (n<1 || s==null) return "";
		StringBuilder sb = new StringBuilder(s.length()*n);
		for (int i=0; i<n; ++i) sb.append(s);
		return sb.toString();
	}
	String str(Object o) {
		if (o==null) return "";
		return o.toString();
	}

	long timer = System.currentTimeMillis();
	void startTimer() {
		timer = System.currentTimeMillis();
	}
	void stopTimer() {
		System.err.println("time: "+(System.currentTimeMillis()-timer)/1000.0);
	}

	static class InputReader {
		private byte[] buf;
		private int bufPos = 0, bufLim = -1;
		private InputStream stream;
		public InputReader(InputStream stream, int size) {
			buf = new byte[size];
			this.stream = stream;
		}
		private void fillBuf() throws IOException {
			bufLim = stream.read(buf);
			bufPos = 0;
		}
		char read() throws IOException {
			if (bufPos>=bufLim) fillBuf();
			return (char)buf[bufPos++];
		}
		boolean hasInput() throws IOException {
			if (bufPos>=bufLim) fillBuf();
			return bufPos<bufLim;
		}
	}

	static InputReader inputReader;
	static BufferedWriter outputWriter;

	char nextChar() throws IOException {
		return inputReader.read();
	}
	char nextNonWhitespaceChar() throws IOException {
		char c = inputReader.read();
		while (c<=' ') c=inputReader.read();
		return c;
	}
	String nextWord() throws IOException {
		StringBuilder sb = new StringBuilder();
		char c = inputReader.read();
		while (c<=' ') c=inputReader.read();
		while (c>' ') {
			sb.append(c);
			c = inputReader.read();
		}
		return new String(sb);
	}
	String nextLine() throws IOException {
		StringBuilder sb = new StringBuilder();
		char c = inputReader.read();
		while (c<=' ') c=inputReader.read();
		while (c!='\n' && c!='\r') {
			sb.append(c);
			c = inputReader.read();
		}
		return new String(sb);
	}
	int nextInt() throws IOException {
		int r = 0;
		char c = nextNonWhitespaceChar();
		boolean neg = false;
		if (c=='-') neg=true;
		else r=c-48;
		c = nextChar();
		while (c>='0' && c<='9') {
			r*=10;
			r+=c-48;
			c=nextChar();
		}
		return neg ? -r:r;
	}
	long nextLong() throws IOException {
		long r = 0;
		char c = nextNonWhitespaceChar();
		boolean neg = false;
		if (c=='-') neg=true;
		else r = c-48;
		c = nextChar();
		while (c>='0' && c<='9') {
			r*=10L;
			r+=c-48L;
			c=nextChar();
		}
		return neg ? -r:r;
	}
	double nextDouble() throws NumberFormatException, IOException {
		return Double.parseDouble(nextWord());
	}
	int[] nextArr(int size) throws NumberFormatException, IOException {
		int[] arr = new int[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextInt();
		return arr;
	}
	long[] nextArrL(int size) throws NumberFormatException, IOException {
		long[] arr = new long[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextLong();
		return arr;
	}
	double[] nextArrD(int size) throws NumberFormatException, IOException {
		double[] arr = new double[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextDouble();
		return arr;
	}
	String[] nextArrS(int size) throws NumberFormatException, IOException {
		String[] arr = new String[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextWord();
		return arr;
	}
	char[] nextArrCh(int size) throws IOException {
		char[] arr = new char[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextNonWhitespaceChar();
		return arr;
	}
	char[][] nextArrCh(int rows, int columns) throws IOException {
		char[][] arr = new char[rows][columns];
		for (int i=0; i<rows; ++i)
			for (int j=0; j<columns; ++j)
				arr[i][j] = nextNonWhitespaceChar();
		return arr;
	}
	char[][] nextArrChBorders(int rows, int columns, char border) throws IOException {
		char[][] arr = new char[rows+2][columns+2];
		for (int i=1; i<=rows; ++i)
			for (int j=1; j<=columns; ++j)
				arr[i][j] = nextNonWhitespaceChar();
		for (int i=0; i<columns+2; ++i) {
			arr[0][i] = border;
			arr[rows+1][i] = border;
		}
		for (int i=0; i<rows+2; ++i) {
			arr[i][0] = border;
			arr[i][columns+1] = border;
		}
		return arr;
	}

	void printf(String format, Object... args) throws IOException {
		outputWriter.write(String.format(format, args));
	}
	void print(Object o) throws IOException {
		outputWriter.write(o.toString());
	}
	void println(Object o) throws IOException {
		outputWriter.write(o.toString());
		outputWriter.newLine();
	}
	void print(Object... o) throws IOException {
		for (int i=0; i<o.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(o[i].toString());
		}
	}
	void println(Object... o) throws IOException {
		print(o);
		outputWriter.newLine();
	}
	void printn(Object o, int n) throws IOException {
		String s = o.toString();
		for (int i=0; i<n; ++i) {
			outputWriter.write(s);
			if (i!=n-1) outputWriter.write(' ');
		}
	}
	void printnln(Object o, int n) throws IOException {
		printn(o, n);
		outputWriter.newLine();
	}
	void printArr(int[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(Integer.toString(arr[i]));
		}
	}
	void printArr(long[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(Long.toString(arr[i]));
		}
	}
	void printArr(double[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(Double.toString(arr[i]));
		}
	}
	void printArr(String[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(arr[i]);
		}
	}
	void printlnArr(int[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void printlnArr(long[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void printlnArr(double[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void printlnArr(String[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void halt(Object... o) throws IOException {
		if (o.length!=0) println(o);
		outputWriter.flush(); outputWriter.close();
		System.exit(0);
	}

	void debug(Object... o) {
		if (showDebug) System.err.println(Arrays.deepToString(o));
	}

	public static void main(String[] args) throws Exception {
		Locale.setDefault(Locale.US);
		if (!useFiles) {
			inputReader = new InputReader(System.in, 1<<16);
			outputWriter = new BufferedWriter(new OutputStreamWriter(System.out), 1<<16);
		} else {
			inputReader = new InputReader(new FileInputStream(new File(inFile)), 1<<16);
			outputWriter = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(new File(outFile))), 1<<16);
		}
		new D().solve();
		outputWriter.flush(); outputWriter.close();
	}
}


import static java.lang.Math.*;
import java.util.*;
import java.io.*;

public class D {

	public void solve() throws Exception {

		int n = nextInt(), m = nextInt(), t = nextInt();
		int[] starts = new int[n];
		for (int i=0; i<n; ++i) {
			String[] s = nextLine().split(":");
			starts[i] = Integer.parseInt(s[0]) * 3600 + Integer.parseInt(s[1]) * 60 + Integer.parseInt(s[2]);
		}

		int max = 0;
		LinkedList<Integer> open = new LinkedList<Integer>();
		LinkedList<Integer> idsFree = new LinkedList<Integer>();
		LinkedList<Integer> idsTaken = new LinkedList<Integer>();
		for (int i=1; i<=n; ++i) idsFree.add(i);
		int idmax = 0;
		LinkedList<Integer> res = new LinkedList<Integer>();
		for (int start: starts) {
			while (!open.isEmpty() && open.peek() <= start) {
				open.poll();
				int idB = idsTaken.poll();
				idsFree.add(idB);
			}
			max = max(max, open.size());
			int id = 0;
			if (open.size() >= m) {
				id = idsTaken.getLast();
				open.remove(open.getLast());
			} else {
				id = idsFree.poll();
				idsTaken.add(id);
			}
			res.add(id);
			idmax = max(idmax, id);
			open.add(start+t);
		}

		if (max<m) {
			println("No solution");
		} else {
			println(idmax);
			for (int id: res) println(id);
		}

	}

	////////////////////////////////////////////////////////////////////////////

	boolean showDebug = true;
	static boolean useFiles = false;
	static String inFile = "input.txt";
	static String outFile = "output.txt";

	double EPS = 1e-7;
	int INF = Integer.MAX_VALUE;
	long INFL = Long.MAX_VALUE;
	double INFD = Double.MAX_VALUE;

	int absPos(int num) {
		return num<0 ? 0:num;
	}
	long absPos(long num) {
		return num<0 ? 0:num;
	}
	double absPos(double num) {
		return num<0 ? 0:num;
	}

	int min(int... nums) {
		int r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]<r) r=nums[i];
		return r;
	}
	int max(int... nums) {
		int r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]>r) r=nums[i];
		return r;
	}
	long minL(long... nums) {
		long r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]<r) r=nums[i];
		return r;
	}
	long maxL(long... nums) {
		long r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]>r) r=nums[i];
		return r;
	}
	double minD(double... nums) {
		double r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]<r) r=nums[i];
		return r;
	}
	double maxD(double... nums) {
		double r = nums[0];
		for (int i=1; i<nums.length; ++i)
			if (nums[i]>r) r=nums[i];
		return r;
	}

	long sumArr(int[] arr) {
		long res = 0;
		for (int i=0; i<arr.length; ++i)
			res+=arr[i];
		return res;
	}
	long sumArr(long[] arr) {
		long res = 0;
		for (int i=0; i<arr.length; ++i)
			res+=arr[i];
		return res;
	}
	double sumArr(double[] arr) {
		double res = 0;
		for (int i=0; i<arr.length; ++i)
			res+=arr[i];
		return res;
	}

	long partsFitCnt(long partSize, long wholeSize) {
		return (partSize+wholeSize-1)/partSize;
	}

	boolean odd(long num) {
		return (num&1)==1;
	}

	boolean hasBit(int num, int pos) {
		return (num&(1<<pos))>0;
	}

	boolean isLetter(char c) {
		return (c>='a' && c<='z') || (c>='A' && c<='Z');
	}
	boolean isLowercase(char c) {
		return (c>='a' && c<='z');
	}
	boolean isUppercase(char c) {
		return (c>='A' && c<='Z');
	}
	boolean isDigit(char c) {
		return (c>='0' && c<='9');
	}

	boolean charIn(String chars, String s) {
		if (s==null) return false;
		if (chars==null || chars.equals("")) return true;
		for (int i=0; i<s.length(); ++i)
			for (int j=0; j<chars.length(); ++j)
				if (chars.charAt(j)==s.charAt(i)) return true;
		return false;
	}

	String stringn(String s, int n) {
		if (n<1 || s==null) return "";
		StringBuilder sb = new StringBuilder(s.length()*n);
		for (int i=0; i<n; ++i) sb.append(s);
		return sb.toString();
	}
	String str(Object o) {
		if (o==null) return "";
		return o.toString();
	}

	long timer = System.currentTimeMillis();
	void startTimer() {
		timer = System.currentTimeMillis();
	}
	void stopTimer() {
		System.err.println("time: "+(System.currentTimeMillis()-timer)/1000.0);
	}

	static class InputReader {
		private byte[] buf;
		private int bufPos = 0, bufLim = -1;
		private InputStream stream;
		public InputReader(InputStream stream, int size) {
			buf = new byte[size];
			this.stream = stream;
		}
		private void fillBuf() throws IOException {
			bufLim = stream.read(buf);
			bufPos = 0;
		}
		char read() throws IOException {
			if (bufPos>=bufLim) fillBuf();
			return (char)buf[bufPos++];
		}
		boolean hasInput() throws IOException {
			if (bufPos>=bufLim) fillBuf();
			return bufPos<bufLim;
		}
	}

	static InputReader inputReader;
	static BufferedWriter outputWriter;

	char nextChar() throws IOException {
		return inputReader.read();
	}
	char nextNonWhitespaceChar() throws IOException {
		char c = inputReader.read();
		while (c<=' ') c=inputReader.read();
		return c;
	}
	String nextWord() throws IOException {
		StringBuilder sb = new StringBuilder();
		char c = inputReader.read();
		while (c<=' ') c=inputReader.read();
		while (c>' ') {
			sb.append(c);
			c = inputReader.read();
		}
		return new String(sb);
	}
	String nextLine() throws IOException {
		StringBuilder sb = new StringBuilder();
		char c = inputReader.read();
		while (c<=' ') c=inputReader.read();
		while (c!='\n' && c!='\r') {
			sb.append(c);
			c = inputReader.read();
		}
		return new String(sb);
	}
	int nextInt() throws IOException {
		int r = 0;
		char c = nextNonWhitespaceChar();
		boolean neg = false;
		if (c=='-') neg=true;
		else r=c-48;
		c = nextChar();
		while (c>='0' && c<='9') {
			r*=10;
			r+=c-48;
			c=nextChar();
		}
		return neg ? -r:r;
	}
	long nextLong() throws IOException {
		long r = 0;
		char c = nextNonWhitespaceChar();
		boolean neg = false;
		if (c=='-') neg=true;
		else r = c-48;
		c = nextChar();
		while (c>='0' && c<='9') {
			r*=10L;
			r+=c-48L;
			c=nextChar();
		}
		return neg ? -r:r;
	}
	double nextDouble() throws NumberFormatException, IOException {
		return Double.parseDouble(nextWord());
	}
	int[] nextArr(int size) throws NumberFormatException, IOException {
		int[] arr = new int[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextInt();
		return arr;
	}
	long[] nextArrL(int size) throws NumberFormatException, IOException {
		long[] arr = new long[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextLong();
		return arr;
	}
	double[] nextArrD(int size) throws NumberFormatException, IOException {
		double[] arr = new double[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextDouble();
		return arr;
	}
	String[] nextArrS(int size) throws NumberFormatException, IOException {
		String[] arr = new String[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextWord();
		return arr;
	}
	char[] nextArrCh(int size) throws IOException {
		char[] arr = new char[size];
		for (int i=0; i<size; ++i)
			arr[i] = nextNonWhitespaceChar();
		return arr;
	}
	char[][] nextArrCh(int rows, int columns) throws IOException {
		char[][] arr = new char[rows][columns];
		for (int i=0; i<rows; ++i)
			for (int j=0; j<columns; ++j)
				arr[i][j] = nextNonWhitespaceChar();
		return arr;
	}
	char[][] nextArrChBorders(int rows, int columns, char border) throws IOException {
		char[][] arr = new char[rows+2][columns+2];
		for (int i=1; i<=rows; ++i)
			for (int j=1; j<=columns; ++j)
				arr[i][j] = nextNonWhitespaceChar();
		for (int i=0; i<columns+2; ++i) {
			arr[0][i] = border;
			arr[rows+1][i] = border;
		}
		for (int i=0; i<rows+2; ++i) {
			arr[i][0] = border;
			arr[i][columns+1] = border;
		}
		return arr;
	}

	void printf(String format, Object... args) throws IOException {
		outputWriter.write(String.format(format, args));
	}
	void print(Object o) throws IOException {
		outputWriter.write(o.toString());
	}
	void println(Object o) throws IOException {
		outputWriter.write(o.toString());
		outputWriter.newLine();
	}
	void print(Object... o) throws IOException {
		for (int i=0; i<o.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(o[i].toString());
		}
	}
	void println(Object... o) throws IOException {
		print(o);
		outputWriter.newLine();
	}
	void printn(Object o, int n) throws IOException {
		String s = o.toString();
		for (int i=0; i<n; ++i) {
			outputWriter.write(s);
			if (i!=n-1) outputWriter.write(' ');
		}
	}
	void printnln(Object o, int n) throws IOException {
		printn(o, n);
		outputWriter.newLine();
	}
	void printArr(int[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(Integer.toString(arr[i]));
		}
	}
	void printArr(long[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(Long.toString(arr[i]));
		}
	}
	void printArr(double[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(Double.toString(arr[i]));
		}
	}
	void printArr(String[] arr) throws IOException {
		for (int i=0; i<arr.length; ++i) {
			if (i!=0) outputWriter.write(' ');
			outputWriter.write(arr[i]);
		}
	}
	void printlnArr(int[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void printlnArr(long[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void printlnArr(double[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void printlnArr(String[] arr) throws IOException {
		printArr(arr);
		outputWriter.newLine();
	}
	void halt(Object... o) throws IOException {
		if (o.length!=0) println(o);
		outputWriter.flush(); outputWriter.close();
		System.exit(0);
	}

	void debug(Object... o) {
		if (showDebug) System.err.println(Arrays.deepToString(o));
	}

	public static void main(String[] args) throws Exception {
		Locale.setDefault(Locale.US);
		if (!useFiles) {
			inputReader = new InputReader(System.in, 1<<16);
			outputWriter = new BufferedWriter(new OutputStreamWriter(System.out), 1<<16);
		} else {
			inputReader = new InputReader(new FileInputStream(new File(inFile)), 1<<16);
			outputWriter = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(new File(outFile))), 1<<16);
		}
		new D().solve();
		outputWriter.flush(); outputWriter.close();
	}
}


//package vk2015.r1;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.Comparator;
import java.util.InputMismatchException;

public class D {
	InputStream is;
	PrintWriter out;
	String INPUT = "";

	void solve()
	{
		int n = ni(), m = ni(), t = ni();
		int[] a = new int[n];
		for(int i = 0;i < n;i++){
			a[i] = ni()*3600+ni()*60+ni();
		}
		if(n < m){
			out.println("No solution");
			return;
		}

		int online = 0;
		int gen = 0;

		int[][] rs = new int[2*n][];
		int[] stands = new int[n+3];
		int[] ids = new int[n];
		Arrays.fill(ids, -1);
		int last = -1;
		for(int i = 0;i < n;i++){
			rs[i] = new int[]{a[i], 1, i};
			rs[i+n] = new int[]{a[i]+t, -1, i};
		}
		Arrays.sort(rs, new Comparator<int[]>() {
			public int compare(int[] a, int[] b) {
				if(a[0] != b[0])return a[0] - b[0];
				return a[1] - b[1];
			}
		});
		boolean ok = false;
		for(int[] r : rs){
			if(r[1] == 1){
				if(online == m){
					ids[r[2]] = last;
					stands[last]++;
				}else{
					ids[r[2]] = last = ++gen;
					stands[last]++;
					online++;
					if(online == m)ok = true;
				}
			}else{
				if(--stands[ids[r[2]]] == 0)online--;
			}
		}
		if(!ok){
			out.println("No solution");
		}else{
			out.println(gen);
			for(int i = 0;i < n;i++){
				out.println(ids[i]);
			}
		}
	}

	void run() throws Exception
	{
		is = oj ? System.in : new ByteArrayInputStream(INPUT.getBytes());
		out = new PrintWriter(System.out);

		long s = System.currentTimeMillis();
		solve();
		out.flush();
		tr(System.currentTimeMillis()-s+"ms");
	}

	public static void main(String[] args) throws Exception { new D().run(); }

	private byte[] inbuf = new byte[1024];
	private int lenbuf = 0, ptrbuf = 0;

	private int readByte()
	{
		if(lenbuf == -1)throw new InputMismatchException();
		if(ptrbuf >= lenbuf){
			ptrbuf = 0;
			try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
			if(lenbuf <= 0)return -1;
		}
		return inbuf[ptrbuf++];
	}

	private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
	private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }

	private double nd() { return Double.parseDouble(ns()); }
	private char nc() { return (char)skip(); }

	private String ns()
	{
		int b = skip();
		StringBuilder sb = new StringBuilder();
		while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ')
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}

	private char[] ns(int n)
	{
		char[] buf = new char[n];
		int b = skip(), p = 0;
		while(p < n && !(isSpaceChar(b))){
			buf[p++] = (char)b;
			b = readByte();
		}
		return n == p ? buf : Arrays.copyOf(buf, p);
	}

	private char[][] nm(int n, int m)
	{
		char[][] map = new char[n][];
		for(int i = 0;i < n;i++)map[i] = ns(m);
		return map;
	}

	private int[] na(int n)
	{
		int[] a = new int[n];
		for(int i = 0;i < n;i++)a[i] = ni();
		return a;
	}

	private int ni()
	{
		int num = 0, b;
		boolean minus = false;
		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
		if(b == '-'){
			minus = true;
			b = readByte();
		}

		while(true){
			if(b >= '0' && b <= '9'){
				num = num * 10 + (b - '0');
			}else{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}

	private long nl()
	{
		long num = 0;
		int b;
		boolean minus = false;
		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
		if(b == '-'){
			minus = true;
			b = readByte();
		}

		while(true){
			if(b >= '0' && b <= '9'){
				num = num * 10 + (b - '0');
			}else{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}

	private boolean oj = System.getProperty("ONLINE_JUDGE") != null;
	private void tr(Object... o) { if(!oj)System.out.println(Arrays.deepToString(o)); }
}