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

const int N = 200000 + 5;

int n;
int a[N];

int main(){
	scanf("%d", &n);
	long long extra = 0, ones = 0, twos = 0;
	for(int i = 0; i < n; i++){
		scanf("%d", a + i);
		if(a[i] == 1) ones += 1;
		else if(a[i] == 2) twos += 1;
		else extra += 1;
	}
	long long ans = 2 * extra * ones + 1 * extra * twos + 3 * ones * twos + 2 * ones * (ones - 1) / 2 + 1 * extra * (extra - 1) / 2 + 1 * twos * (twos - 1) / 2;
	printf("%lld\n", ans);
	return 0;
}