#include <fstream>
using namespace std;
ifstream fin("energii.in");ofstream fout("energii.out");
int g,w,CG[5001],ep[10001],rez[5001][10001],i,key,j;
int main()
{
    fin>>g>>w;
    for(i=1;i<=g;i++) fin>>CG[i]>>ep[i];
    for(i=1;i<=g;i++,key=1-key)
        for(j=1;j<=w;j++)
        {
            rez[1-key][j]=rez[key][j];
            if(CG[i]<=j) rez[1-key][j]=max(rez[1-key][j],rez[key][j-CG[i]]+ep[i]);
        }
    fout<<rez[key][w];
    return 0;
}