#include <iostream>
#include <stdio.h>
using namespace std;


struct produs{
    int g,p;
};
produs v[5000];
int main()
{
    int profit[5000];
    int m,k,n;
    FILE *in,*out;
    in=fopen("rucsac.in","r");
    fscanf(in,"%d%d",&n,&k);
    for(int i=1;i<=n;i++){
        fscanf(in,"%d%d",&v[i].g,&v[i].p);
    }

    for(int i=1;i<=k;i++) profit[i]=-1;
    profit[0]=0;
    for(int i=1;i<=n;i++){
        for(int j=k-v[i].g;j>=0;j--){
            if(profit[j]!=-1&&profit[j]+v[i].p>profit[j+v[i].g])
            profit[j+v[i].g]=profit[j]+v[i].p;
        }
    }

    out=fopen("rucsac.out","w");
    fprintf(out,"%d",profit[k]);

    return 0;
}