#include <bits/stdc++.h>

using namespace std;
using ll = long long;

int n;
ll cnt[3];

int main() {

  cin >> n;
  for (int i = 0; i < n; ++i) {
    int A;
    cin >> A;
    if (A > 3)
      A = 3;
    ++cnt[A - 1];
  }

  ll ans = 0;
  ans +=
      cnt[1] * (cnt[1] - 1) / 2 + cnt[2] * (cnt[2] - 1) / 2 + cnt[1] * cnt[2];
  ans += cnt[0] * (cnt[0] - 1) + 2 * cnt[0] * cnt[2];
  ans += 3 * cnt[0] * cnt[1];

  cout << ans << '\n';

  return 0;
}