#include <bits/stdc++.h>

using namespace std;

using ll = long long;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n;
    cin >> n;
    bool f0 = false;
    ll ans = 1;
    for (int i = 0; i < n; i++) {
        ll p;
        cin >> p;
        if (p == 0) f0 = true;
        (ans *= p) %= 9;
    }
    if (!f0 && ans == 0) ans = 9;
    cout << ans << "\n";
    return 0;
}