#include <bits/stdc++.h>

using namespace std;

long long dp[10001];
int main()
{
    ifstream cin("rucsac.in");
    ofstream cout("rucsac.out");

    int n, gmax;
    cin >> n >> gmax;
    dp[0] = 1;
    for(int i = 1; i <= n; i ++)
    {
        int g, p;
        cin >> g >> p;
        for(int j = gmax; j >= g; j --)
        {
            if(dp[j - g] != 0 and dp[j - g] + p > dp[j])
                dp[j] = dp[j - g] + p;
        }
    }
    cout << dp[gmax] - 1;
    return 0;
}