#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) begin(v),end(v)
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
using ll = long long;
using pii = pair<int, int>;
constexpr ll INF = 1ll<<30;
constexpr ll longINF = 1ll<<60;
constexpr ll MOD = 1000000007;
constexpr bool debug = false;
//---------------------------------//

int main() {
	int N;
	cin >> N;
	ll c[3] {};
	REP(i, N) {
		int a;
		scanf("%d", &a);
		c[0] += a == 1;
		c[1] += a == 2;
		c[2] += a > 2;
	}
	ll ans = 0;
	REP(i, 3) FOR(j, i, 3) {
		if (i == j) ans += (c[i] * (c[i] - 1) / 2) * (i == 0 ? 2 : 1);
		else {
			int mex = 1;
			if (i == 0 || j == 0) mex = 2;
			if (mex == 2 && (i == 1 || j == 1)) mex = 3;
			ans += (c[i] * c[j]) * mex;
		}
	}
	cout << ans << endl;
}