#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;

int main() {
    long long N;
    cin >> N;
    long long a[N];
    for (int i = 0; i < N; i++) cin >> a[i];
    unordered_set<long long> dp[N];
    dp[0].insert(a[0]);
    for (int i = 1; i < N; i++) {
        for (auto x : dp[i - 1]) {
            dp[i].insert(x + a[i]);
            dp[i].insert(x - a[i]);
            dp[i].insert(x * a[i]);
            if (a[i] != 0) dp[i].insert(x / a[i]);
        }
    }
    cout << *max_element(dp[N - 1].begin(), dp[N - 1].end()) << endl;
}