#include <fstream>

using namespace std;
ifstream f("rucsac.in");
ofstream g("rucsac.out");
int gmax,pmax,i,nr,gg[10000000],pp[10000000],h,hp,hg,n;
int main()
{
    f>>n>>gmax;pmax=0;nr=0;
    for(h=1;h<=n;++h)
    {
        f>>hg>>hp;
        for(i=nr;i>=1;--i)
        if(gg[i]+hg<=gmax && gg[i]>0) {gg[++nr]=gg[i]+hg;pp[nr]=pp[i]+hp;}
        gg[++nr]=hg;
        pp[nr]=hp;
    }

    for(i=1;i<=nr;++i) if(pp[i]>pmax) pmax=pp[i];
    g<<pmax<<'\n';



    return 0;
}