#include <iostream>
#include <vector>
using namespace std;
using ll = long long int;

int main(){
    int n;
    cin >> n;
    vector<int> a(n);
    for(auto &p: a) cin >> p;
    
    int cnt1 = 0, cnt2 = 0, cnt3 = 0;
    for(auto &p: a){
        if(p == 1) cnt1++;
        else if(p == 2) cnt2++;
        else if(p == 3) cnt3++;
    }

    ll ans = (ll)n*(n-1)/2;
    ans += (ll)cnt1*(cnt1-1)/2;
    ans += (ll)cnt1*cnt2*2;
    ans += (ll)cnt1*(n-cnt1-cnt2);
    cout << ans << endl;
    return 0;
}