#include <cstdio>
#include <vector>
using namespace std;
int i,j,k,l,m,n,max1,x,y,g1,g[5000],v[5000],prins[5000][5000],gr[5000],vr[5000],hot,ruc;
void rucsacfraier()
{
    for(i=0;i<g1+1;i++)
        {
            for(j=i;j>-1;j--)
                 for(k=1;k<n+1;k++)
                     if(prins[j][k]==0)  if(g[k]+gr[j]<=i)
                                              if(v[k]+vr[j]>max1) {max1=v[k]+vr[j]; hot=k; ruc=j;}
             for(j=1;j<n+1;j++)
                prins[i][j]=prins[ruc][j];
                prins[i][hot]=1;
                max1=0;
                vr[i]=v[hot]+vr[ruc];
                gr[i]=g[hot]+gr[ruc];
                hot=0;
        }
}
int main()
{
   freopen("rucsac.in","r",stdin);
   freopen("rucsac.out","w",stdout);
    scanf("%d %d",&n,&g1);
    for(i=1;i<n+1;i++)
      scanf("%d %d",&g[i],&v[i]);
    rucsacfraier();
    printf("%d",vr[g1]);
    return 0;
}