#include <bits/stdc++.h>
using namespace std;
using ll = long long;
ll N, W;
ll v[20],w[20];
ll solve(ll R, ll S) {
    vector<ll>dp(R+1);
    dp[0]=S;
    for(int i = 0; i < N; i++) {
        for(int j = 0; j <= R-w[i]; j++) {
            dp[j+w[i]]=max(dp[j+w[i]], dp[j]+v[i]);
        }
    }
    ll ret=0;
    for(int i = 0; i <= R; i++) ret=max(ret,dp[i]);
    return ret;
}
int main() {
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(nullptr);
    cin >> N >> W;
    for(int i = 0; i < N; i++) cin >> v[i] >> w[i];
    ll ans = 0;
    for(int i = 0; i < N; i++) {
        ll p = W-W/w[i]*w[i];
        ll q = W/w[i]*v[i];
        cerr << "???" << p << " " << q << "\n";
        ans=max(ans,solve(p,q));
    }
    cout << ans << "\n";
}