#include <bits/stdc++.h>

using namespace std;
int n,k,rez=0;
struct sigma
{
    int cost,greutate;
};
sigma v[5005];
 void Rezolv(int a,int b,int c)
{
    if(a==n+1)
    {
        if(c<=k)
            rez=max(rez,b);
    }
    else
    {
        if(c+v[a].greutate<=k)
            Rezolv(a+1,b+v[a].cost,c+v[a].greutate);
        Rezolv(a+1,b,c);
    }
}
int main()
{
    ifstream cin("rucsac.in");
    ofstream cout("rucsac.out");
  cin>>n>>k;
  for(int i=1;i<=n;i++)
    cin>>v[i].greutate>>v[i].cost;
  Rezolv(1,0,0);
  cout<<rez;
    return 0;
}