#include "bits/stdc++.h"
//#define int long long
using namespace std;
using ll = long long;
using P = pair<ll, ll>;
const ll INF = (1LL << 61);
ll mod = 1000000007;


signed main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	int N; cin >> N;
	vector<ll>A(N); for (int i = 0; i < N; i++)cin >> A[i];
	vector<ll>cnt(4);
	for (int i = 0; i < N; i++) {
		cnt[min(3LL, A[i])]++;
	}
	ll ans = 0;
	ans += cnt[1] * (cnt[1] - 1);
	ans += cnt[2] * (cnt[2] - 1) / 2;
	ans += cnt[3] * (cnt[3] - 1) / 2;
	ans += cnt[1] * cnt[2] * 3;
	ans += cnt[1] * cnt[3] * 2;
	ans += cnt[2] * cnt[3];
	cout << ans << endl;
	return 0;
}