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

class Main {

    static class Reader {
        final private int BUFFER_SIZE = 1 << 16;
        private DataInputStream din;
        private byte[] buffer;
        private int bufferPointer, bytesRead;

        public Reader() {
            din = new DataInputStream(System.in);
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        public Reader(String file_name) throws IOException {
            din = new DataInputStream(new FileInputStream(file_name));
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        public String readLine() throws IOException {
            byte[] buf = new byte[64]; // line length
            int cnt = 0, c;
            while ((c = read()) != -1) {
                if (c == '\n')
                    break;
                buf[cnt++] = (byte) c;
            }
            return new String(buf, 0, cnt);
        }

        public int nextInt() throws IOException {
            int ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');

            if (neg)
                return -ret;
            return ret;
        }

        public long nextLong() throws IOException {
            long ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (neg)
                return -ret;
            return ret;
        }

        public double nextDouble() throws IOException {
            double ret = 0, div = 1;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();

            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');

            if (c == '.') {
                while ((c = read()) >= '0' && c <= '9') {
                    ret += (c - '0') / (div *= 10);
                }
            }

            if (neg)
                return -ret;
            return ret;
        }

        private void fillBuffer() throws IOException {
            bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE);
            if (bytesRead == -1)
                buffer[0] = -1;
        }

        private byte read() throws IOException {
            if (bufferPointer == bytesRead)
                fillBuffer();
            return buffer[bufferPointer++];
        }

        public void close() throws IOException {
            if (din == null)
                return;
            din.close();
        }
    }

    static final Reader in = new Reader();
    static int N, W;
    static int[] w;
    static int[] v;
    static int[] c;


    static long[][] dp;

    public static void main(String[] args) throws Exception {
        N = in.nextInt();
        W = in.nextInt();
        w = new int[N + 1];
        v = new int[N + 1];

        dp = new long[N + 1][W + 1];

        for (int i = 1; i <= N; i++) {
            w[i] = in.nextInt();
            v[i] = in.nextInt();
            
            Arrays.fill(dp[i],-1);
        }
		K_topdown();
        System.out.println(dp[N][W]);
        
    }

    static void K_topdown() {
        // base condition
        for(int c = 0;c < W;c++)
          dp[0][c] = 0;

        //..start filling the matrix  
      	for(int i = 1;i <= N;i++){
          for(int c = 0;c <= W;c++){
            
            if (w[i] <= c) {
                    long temp1 = dp[i-1][c];
                    long temp2 = v[i] + dp[i - 1][c - w[i]];
                dp[i][c] = Math.max(temp1, temp2);
            }
            else  //..weight of ith element is more than c     
                dp[i][c] = dp[i - 1][c]; 
          }
        }
        
    }

}


Measured memory_bytes: 137940