#include <fstream>

using namespace std;
ifstream f ("rucsac.in");
ofstream g ("rucsac.out");
int n,p,gr,G,i,j,MAX,x,a[5002],b[5003];
int main()
{
    f>>n>>gr;
    for (i=1;i<=n;i++)
    f>>a[i]>>b[i];
    for (i=1;i<(1<<n);i++)
    {
        x=i;
        p=0;
        G=0;
        for (j=1;j<=n;j++)
        {
            if (x%2==1)
            {
            G=G+a[j];
            p=p+b[j];
            }
            x=x/2;
        }
        if (G<=gr && p>MAX)
        MAX=p;
    }
    g<<MAX<<'\n';
    return 0;
}