#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cstring>
#include <cstdlib>
#include <cmath>
using namespace std;
using ll = long long;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    int n;
    cin >> n;

    ll r = 1;
    for (int i = 0; i < n; i++) {
        int p;
        cin >> p;
        r = r * p % 9;
    }

    cout << r << endl;

    return 0;
}