/*input
6 15
6 5
5 6
6 4
6 6
3 5
7 2
*/
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.PriorityQueue;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
import java.util.Arrays;
import java.util.StringTokenizer;
import java.io.BufferedReader;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author masterbios
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        CLinovaAndKingdom solver = new CLinovaAndKingdom();
        solver.solve(1, in, out);
        out.close();
    }

    static class CLinovaAndKingdom {

        final int MAXN = (int) 1e5 + 10;
       
        long dp[][] = new long[102][MAXN];
        int val[] = new int[102];
        int weight[] = new int[102];

        public void solve(int testNumber, InputReader in, PrintWriter out) {
            int n = in.nextInt(), wt = in.nextInt();
            for (int i = 0; i < n; i++) {
                weight[i] = in.nextInt(); val[i] = in.nextInt();
            }
            for (int i = 0; i <= n; i++) {
                for (int j = 0; j <= wt; j++) dp[i][j] = -1;
            }
            out.println(solve(0, n, wt));
        }

        public long solve(int idx, int n, int wt) {
            if (idx == n) return 0;
            if (dp[idx][wt] != -1) return dp[idx][wt];
            long ans = solve(idx + 1, n, wt);
            if (wt >= weight[idx]) {
                ans = max(ans, val[idx] + solve(idx + 1, n, wt - weight[idx]));
            }
            return dp[idx][wt] = ans;
        }


        public int max(int ...a) {
            int max = Integer.MIN_VALUE;
            for (int i : a) max = Math.max(max, i);
            return max;
        }

        public int min(int ...a) {
            int min = Integer.MAX_VALUE;
            for (int i : a) min = Math.min(min, i);
            return min;
        }

        public long max(long ...a) {
            long max = Long.MIN_VALUE;
            for (long i : a) max = Math.max(max, i);
            return max;
        }

        public long min(long ...a) {
            long min = Long.MAX_VALUE;
            for (long i : a) min = Math.min(min, i);
            return min;
        }

    }

    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreElements()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

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

    }
}



Measured memory_bytes: 206828