#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); i++)
using namespace std;
typedef long long ll;

int main(){
    cin.tie(0);
    ios::sync_with_stdio(0);
    
    int N; cin >> N;
    ll C1 = 0, C2 = 0, OTHER = 0;
    rep(i,N) {
        int A; cin >> A;
        if(A == 1) C1++;
        else if(A == 2) C2++;
        else OTHER++;
    }

    ll ans = 0;
    ans += (2LL) * C1 * (C1 - 1) / 2;
    ans += (1LL) * C2 * (C2 - 1) / 2;
    ans += (3LL) * C1 * C2;
    ans += (2LL) * C1 * OTHER;
    ans += (1LL) * C2 * OTHER;
    ans += (1LL) * OTHER * (OTHER - 1) / 2;
    cout << ans << endl;
}