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

int main() {
    cin.tie(nullptr), ios::sync_with_stdio(false);
    int N, a;
    cin >> N;
    vector<long long> n(3);
    for (int i = 0; i < N; i++) {
        cin >> a, a--;
        n[min(a, 2)]++;
    }
    cout << n[0] * (n[0] - 1) / 2 + n[0] * n[1] * 2 + n[0] * n[2] + 1LL * N * (N - 1) / 2 << '\n';
}