#include <iostream>
#include <algorithm>

#define INF 114514191

using namespace std;

int N, a[20], dp[20];

int rec(int idx) {
    if(idx == 0) return a[0];
    if(dp[idx] != -INF) return dp[idx];

    int ret = -INF;
    int res = rec(idx - 1);

    if(res != 0) {
        ret = res / a[idx];
    }
    ret = max(ret, res + a[idx]);
    ret = max(ret, res - a[idx]);
    ret = max(ret, res * a[idx]);

    return dp[idx] = ret;
}

int main() {
    cin >> N;
    for(int i = 0; i < N; i++) {
        cin >> a[i];
    }

    fill_n(dp, 20, -INF);
    cout << rec(N - 1) << endl;
}