#include <stdio.h>

int main() {
	int n, ans = 1;
	long long int tmp;
	bool zero = false;
	scanf("%d", &n);
	for (int i = 0; i < n; i++) {
		scanf("%lld", &tmp);
		if (tmp == 0) zero = true;
		tmp %= 9;
		ans = ans * tmp % 9;
	}
	if (ans == 0 && !zero) ans = 9;
	printf("%d\n", ans);
}