#include <fstream>

using namespace std;

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

const int NMAX = 5000;
const int GMAX = 10001;

int w[NMAX], p[NMAX], profit[GMAX];

int main()
{
    int n, g, i, j, maxim=-2;
    in>>n>>g;
    for(j=1; j<=g; j++)
        profit[j]=-1;
    profit[0]=0;
    for(i=0; i<n; i++)
    {
        in>>w[i]>>p[i];
    }
    for(i=0; i<n; i++)
    {
        for(j=g-w[i]; j>=0; j--)
        {
            if(profit[j]!=-1 && profit[j]+p[i]>profit[j+w[i]])
            {
                profit[j+w[i]]=profit[j]+p[i];
            }
        }
    }
    for(j=1; j<=g; j++)
    {
        if(profit[j]>maxim)
            maxim=profit[j];
    }
    out<<maxim;
    in.close();
    out.close();
    return 0;
}