#include <fstream>
#define NM 5005

using namespace std;

int d[2][NM];
int gr[NM], p[NM], n, m;

int main()
{
    ifstream f("rucsac.in");
    ofstream g("rucsac.out");

    bool w = 0;
    f >> n >> m;
    for(int i = 1; i <= n; ++i)
        f >> gr[i] >> p[i];

    for(int i = 1; i <= n; ++i)
    {
        for(int j = 0; j <= m; ++j)
        {
            d[0^w][j] = d[1^w][j];
            if(gr[i] <= j)
                d[0^w][j] = max(d[0^w][j], d[1^w][j-gr[i]]+p[i]);
        }
        w ^= 1;
    }

    g << d[1^w][m];
}