#include <iostream>
#include <vector>
#include <utility>
#include <map>
#include <algorithm>
#include <queue>
#include <cmath>

using namespace std;

int main() {
    int n;
    cin >> n;
    long long ans = 1;
    for (int i=0; i<n; i++) {
        long long p;
        cin >> p;
        if (p>0) p = (p%9==0? 9 : p%9);
        ans *= p;
    }
    if (ans>0) ans = (ans%9==0? 9 : ans%9);

    cout << ans << endl;
}