#include "bits/stdc++.h"
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;

using ll = long long;

int main() {
    int N;
    cin >> N;
    ll ans = 1, P;
    rep(i, N) {
        cin >> P;
        if (P == 0) {
            cout << 0 << endl;
            return 0;
        }
        ans = (ans * (P % 9)) % 9;
    }
    cout << (ans + 8) % 9 + 1 << endl;
}