#include <stdio.h>
#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000000000000

int main(){
	
	int N;
	cin>>N;
	
	vector<long long> t(3,0LL);
	rep(i,N){
		int A;
		cin>>A;
		A--;
		t[min(2,A)]++;
	}
	
	long long ans = 0LL;
	ans += t[0]*(t[0]-1)/2 * 2;
	ans += t[0]*t[1] * 3;
	ans += t[0]*t[2] * 2;
	ans += t[1]*(t[1]-1)/2;
	ans += t[1]*t[2];
	ans += t[2]*(t[2]-1)/2;
	
	cout<<ans<<endl;
	
    return 0;
}