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

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

#define VP vector<pair<int,int>>

int N, G;
int maxi = 0;
VP obiect;

void maxProfit(int indice, int sum, int weight) {
    sum += obiect[indice].second, weight += obiect[indice].first;
    if (weight >= G) {
        if (weight > G) {
            sum -= obiect[indice].second;
        }
        maxi = max(maxi, sum);
        return;
    }
    for (int i = indice + 1; i < N; ++i) {
        maxProfit(i, sum, weight);
    }
}

int main() {
    fin >> N >> G;
    obiect = VP(N+1);
    for (int i = 0; i < N; ++i) {
        fin >> obiect[i].first >> obiect[i].second;
    }
    for (int i = 0; i < N; ++i) {
        maxProfit(i, 0, 0);
    }
    fout << maxi;
}