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

#define ll long long
#define rep(i, n) for (int i = 0; i < (n); i++)
#define P pair<int, int>

int main() {
  ll n;
  cin >> n;
  vector<int> a(n);
  rep(i, n) cin >> a[i];
  ll cnt1 = 0, cnt2 = 0, others = 0;
  rep(i, n) {
    if (a[i] == 1) cnt1++;
    if (a[i] == 2) cnt2++;
  }
  others = n-cnt1-cnt2;

  ll ans = 0;
  ll num3 = cnt2*cnt1, num2 = cnt1*(cnt1-1)/2+ cnt1*others, num1 = n*(n-1)/2 - num2 - num3;
  ans += 3*num3;
  ans += 2*num2;
  ans += num1; 
  cout << ans << endl;

}