#include <bits/stdc++.h>
using namespace std;

using ll = long long;

int main() {
    int n;
    cin >> n;
    ll res = 1;
    for (int i = 0; i < n; i++) {
        ll a;
        cin >> a;
        if (a == 0) {
            cout << 0 << endl;
            return 0;
        }
        else {
            res *= a % 9 == 0 ? 9 : a % 9;
            res = res % 9 == 0 ? 9 : res % 9;
        }
    }
    
    cout << (res % 9 == 0 ? 9 : res % 9) << endl;
}