#include <iostream>
#include <fstream>

using namespace std;

int main()
{
    fstream be("rucsac.in", ios::in);
    fstream ki("rucsac.out", ios::out);
    int n, w[5001], p[5001], g, Sw = 0, Sp = 0;
    be >> n >> g;
    for(int i = 1; i <= n; i++){
        be >> w[i] >> p[i];
    }
    for(int i = 1; i <= n; i++){
        Sw += w[i];
    }
    if (Sw <= g){
        for(int i = 1; i <= n; i++){
            Sp += p[i];
        }
        ki << Sp;
    }


    return 0;
}