#include <bits/stdc++.h>
using namespace std;

long long count_1, count_2;
int main() {
	int n;
	cin >> n;
	for(int i = 0; i < n; i++) {
		int a;
		cin >> a;
		if(a == 1) count_1++;
		if(a == 2) count_2++;
	}
	cout << count_1 * (count_2 * 2 + n - 1) + (n - count_1 - count_2) * (n - count_1 - count_2 - 1) << endl;
}