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

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

int main(){
    ifstream fin("rucsac.in");
    ofstream fout("rucsac.out");
    int n, k;
    fin>>n>>k;
    for(int i = 1; i <= n; i++){
        fin>>g[i]>>p[i];
    }


    profit[0] = 0;
    for(int i = 1; i <= k; i++)
        profit[i] = -1;

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

    fout<<profit[k];


    fin.close();
    fout.close();
    return 0;
}