#include <fstream>

using namespace std;

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

int n,gm,i,j,maxim,g[5005],p[5005],d[10005];

int main()
{
    fin >> n >> gm;
    for (i=1;i<=gm;i++) d[i]=-1;
    for (i=1;i<=n;i++) fin >> g[i] >> p[i];
    maxim=-1;
    for (i=1;i<=n;i++) for (j=gm;j>=0;j--) if (d[j]!=-1)
    {
        if (j+g[i]<=gm)
        {
            d[j+g[i]]=max(d[j+g[i]],d[j]+p[i]);
            maxim=max(maxim,d[j+g[i]]);
        }
    }
    fout << maxim;

    return 0;
}