#include <iostream>
#include <fstream>
using namespace std;
FILE *f,*g;

int a[1002][5002];
int main()

{int n,W,i,j,EG[1002],CG[1002];
 f=fopen("energii.in","r");
 g=fopen("energii.out","w");
 fscanf(f,"%d", &n);
 fscanf(f,"%d", &W);
 for(i=1;i<=n;i++)
     for(j=1;j<=W;j++)
        {fscanf(f,"%d", &EG[i]);
         fscanf(f,"%d", &CG[i]);}
for(i=1;i<=n;i++)
    for(j=1;j<=W;j++)
        if(EG[i]>j) a[i][j]=a[i-1][j];
        else a[i][j]=max(CG[i]+a[i-1][j-EG[i]],a[i-1][j]);
fprintf(g,"%d", a[n][W]);
return 0;
}