#include <fstream.h>
#include <iostream.h>
  int main()
  { ifstream f("energii.in");
    ofstream gf("energii.out");
    short int g,w,i,c,e,s;
    float ef[1001],v[1001],u[1001],aux;
    f>>g;
    f>>w;
    for(i=1;i<=g;i++)
    {f>>v[i]>>u[i];}
     for(i=1;i<=g;i++)
     {  ef[i]=v[i]/u[i];}
       do
	   {
		 c=1;
	   for(i=1;i<=g-1;i++)
	   { if (ef[i]<ef[i+1])
	       {aux=v[i];
		v[i]=v[i+1];
		v[i+1]=aux;
		aux=u[i];
		u[i]=u[i+1];
		u[i+1]=aux;
		aux=ef[i];
		ef[i]=ef[i+1];
		ef[i+1]=aux;
		c=0;
		} } }
	while (c==0);
	     s=0;
	     i=1;
	     e=0;
	 do
	   { e=e+v[i];
	     s=s+u[i];
	     i++; }
	 while((i<=g) && (e<w));
	 gf<<s;
         return 0;
      }