#include <iostream>
#include<fstream>

using namespace std;

int main()
{ int n,min,m,G,profit,gr,i,j, v[500],p[500];
 ifstream f("rucsac.in");
 ofstream g("rucsac.out");
 f>>n>>gr; profit=0; G=0;
 for (i=1;i<=n;i++) f>>v[i]>>p[i];
 for(i=1;i<=n;i++) {G=G+v[i]; profit=profit+p[i];}
  do{min=p[i];m=v[i];
   for(i=1;i<=n;i++) if(min>p[i]&&m>v[i]) {min=p[i]; m=v[i];}
    G=G-m; profit=profit-min;
  } while (G>gr);

  g<<profit;
  f.close(); g.close();

    return 0;
}