#include <iostream>
#include <fstream>

using namespace std;

ifstream in("rucsac.in");
ofstream out("rucsac.out");

const int dim = 5005;

int n,w[dim],p[dim],rasp[10005],g;

int main()
{
    int i,j;
    in >> n >> g;
    for (i=1; i<=n; i++)
    {
        in >> w[i] >> p[i];
    }
    for (i=1; i<=g; i++)
    {
        rasp[i] = -1;
    }
    rasp[0] = 0;
    for (i=1; i<=n; i++)
    {
        for (j=g; j>=w[i]; j--)
        {
            if (rasp[j-w[i]] != -1 && rasp[j] < rasp[j-w[i]] + p[i])
            {
                rasp[j] = rasp[j-w[i]] + p[i];
            }
        }
    }
    /*for (i=1; i<=g; i++)
    {
        cout << rasp[i] << " ";
    }*/
    out << rasp[g];
    return 0;
}