#include <iostream>
#include <cstdio>
using namespace std;
int n,lim;
int p[10001],profit[10001],g[10001];

int main()
{
    freopen("rucsac.in","r",stdin);
    freopen("rucsac.out","w",stdout);
    cin>>n>>lim;
    int i,j;
    for(i=1; i<=n; i++)
        cin>>g[i]>>p[i];

    for(j=1; j<=lim; j++)
        profit[j]=-1;
    profit[0]=0;

    for(i=1; i<=n; i++)
        for(j=lim-g[i]; j>=0; j--)
            if(profit[j]!=-1 and profit[j]+p[i]>profit[j+g[i]])
                profit[j+g[i]]=profit[j]+p[i];

    cout<<profit[lim];
    return 0;
}