#include <fstream>

using namespace std;
ifstream f("rucsac.in");
ofstream g("rucsac.out");
int j,i,gmax,gg,n,p,Max;
long long a[50003];
int main()
{
    f>>n>>gmax>>gg>>p;


    for(j=1;j<=n;++j)
    {f>>gg>>p;
    for(i=5000;i>=0;--i)
    if(a[i]>0 && i+gg<=gmax)
        {if(a[i+gg]==0) a[i+gg]=a[i]+p;
         else if(a[i+gg]<a[i]+p) a[i+gg]=a[i]+p;}

    if( a[gg]==0) a[gg]=p;
    else if(a[gg]<p) a[gg]=p;

    }
    Max=0;
    for(i=0;i<=gmax;++i) if(Max<a[i]) Max=a[i];
    g<<Max<<'\n';



    return 0;
}