#include <algorithm>
#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define all(x) (x).begin(), (x).end()
#define ll long long
#define INF 1000000000000000000

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

    int N;
    cin >> N;
    vector<ll> A(N);
    ll a = 1;
    rep(i, N) {
        cin >> A[i];
        a *= A[i];
        if (a % 9 == 0 && a != 0)
            a = 9;
        else
            a %= 9;
    }

    cout << a << endl;

    return 0;
}