#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("YES");}else{puts("NO");}
#define MAX_N 200005

int main() {
    ll n; cin >> n;
    ll f[3] = {};
    rep(i,n){
        int a; cin >> a;
        if(a > 2) a = 0;
        f[a]++;
    }

    ll ans = n*(n-1)/2 + f[0]*f[1] + f[1]*(f[1]-1)/2 + f[1]*f[2]*2;

    cout << ans << endl;
    return 0;
}