#include <bits/stdc++.h>
#define NMAX 1001
#define MMAX 5001
#define INF 1LL<<63

using namespace std;

ifstream fin("energii.in");
ofstream fout("energii.out");

int DP[NMAX][MMAX], E[NMAX], C[NMAX];
int n, m;

int main()
{
    fin >> n >> m;
    for(int i = 1; i <= n; i++) {
        fin >> E[i] >> C[i];
    }
    for(int i = 1; i <= n; i++) {
        for(int j = 1; j <= m; j++) {
            if(E[i] <= j)
                DP[i][j] = DP[i - 1][j - E[i]] + C[i];
        }
    }
    fout << DP[n][m] << '\n';
    return 0;
}