#include <cstdio>
#include <algorithm>
using namespace std;
int d[10001], p[5001], w[5001];
int main()
{
    int i, n, x, y, g, last = 0, profit = -1, j;
    freopen("rucsac.in","r",stdin);
    freopen("rucsac.out","w",stdout);
    scanf("%d%d", &n, &g);
    for(i=1; i<=n; ++i){
        scanf("%d%d", &x, &y);
        p[i] = y;
        w[i] = x;
    }
    for(i=1; i<=n; ++i)
        d[i] = -1;
    d[0] = 0;
    for(i=1; i<=n; ++i){
        for(j = last; j >= 0; --j){
            if(j + w[i] <= g && d[j] != -1){
                d[j + w[i]] = max(d[j + w[i]], d[j] + p[i]);
                if(last < j + w[i])
                    last = j + w[i];
            }
        }
    }
    for(i = g; i >= 0; --i)
        if(d[i] > profit)
            profit = d[i];
    printf("%d", profit);
    return 0;
}