#include <string>
#include <iostream>
using namespace std;
int main() {
	int N;
	cin >> N;
	int mul = 1;
	for(int i = 0; i < N; ++i) {
		int x;
		cin >> x;
		mul = (mul == 0 || x == 0 ? 0 : (1LL * mul * x + 8) % 9 + 1);
	}
	cout << mul << endl;
	return 0;
}