#include <bits/stdc++.h>

using namespace std;

int main() {
   ios::sync_with_stdio(false);
   cin.tie(0);
   int n;
   cin >> n;
   vector<int> a(n);
   long long cnt1 = 0, cnt2 = 0;
   for (int i = 0; i < n; i++) {
       cin >> a[i];
       cnt1 += (a[i] == 1);
       cnt2 += (a[i] == 2);
   }
   long long cnt3 = n - cnt1 - cnt2;
   long long ans = 0;
   ans += cnt1 * cnt2 * 3;
   ans += cnt1 * cnt3 * 2 + cnt1 * (cnt1 - 1) / 2 * 2;
   ans += cnt2 * (cnt2 - 1) / 2 + cnt2 * cnt3 + cnt3 * (cnt3 - 1) / 2;
   cout << ans << endl;
}