#include <cstdio>
#include <iostream>

using namespace std;

const int nmx = 10002;

int dp[nmx];

int main()
{
    freopen("rucsac.in", "r", stdin);
    freopen("rucsac.out", "w", stdout);

    int gmax = 0,n,x;

    scanf("%d %d", &n, &x);
    for(int i = 1; i <= n; ++i)
    {
        int val,greutate;
        scanf("%d %d", &greutate, &val);

        gmax += greutate;
        gmax = min(gmax,x);

        for(int j = gmax; j >= greutate; --j)
            dp[j] = max(dp[j],dp[j-greutate] + val);

    }

    int maxim = -1;

    for(int i = 1; i <= x; ++i)
        maxim = max(maxim,dp[i]);

    printf("%d\n", maxim);

    return 0;
}