#include <fstream>
#include <iostream>
using namespace std;

ifstream in("rucsac.in");
ofstream out("rucsac.out");

int profit[10001];
int p[5002], g[5002];

int main(){
    int n, k;
    cin >> n >> k;

    for(int i=0; i<n; i++)
        cin >> g[i] >> p[i];

    for(int j=1; j<=k; j++)
        profit[j] = -1;

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

    cout << profit[k];
}