#include <iostream>

using namespace std;

int main() {
    int mn_mul = 1000001;
    int mn = 1001;
    int n, i;

    cin >> n;
    int a[7];
    for (i = 0; i < 6; i++)
        cin >> a[i % 7];

    for (i = 6; i < n; i++) {
        cin >> a[i % 7];
        if (a[(i-6) % 7] < mn)
            mn = a[(i-6) % 7];
        if (a[i % 7] * mn < mn_mul)
            mn_mul = a[i % 7] * mn;
    }

    cout << mn_mul << endl;

    return 0;
}