import java.util.Scanner;
import java.lang.Math;

public class Main {
    static final int N =1010;
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();

        int[] v = new int[N];
        int[] w = new int[N];

        for(int i=1;i<=n;i++){
            v[i] = sc.nextInt();
            w[i] = sc.nextInt();
        }

        int[][] f = new int[N][N];
        for(int i=1;i<=n;i++){
            for(int j=0;j<=m;j++){
                for(int k=0; k*v[i]<=j;k++){
                    f[i][j] = Math.max(f[i][j],f[i-1][j-v[i]*k]+w[i]*k);
                }
            }
        }
        System.out.println(f[n][m]);
    }
}