#include <cstdio>
#include <cstring>
#include <iostream>
#include <string>
#include <cmath>
#include <bitset>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <algorithm>
#include <complex>
#include <unordered_map>
#include <unordered_set>
#include <random>
#include <cassert>
#include <fstream>
#include <utility>
#include <functional>
#include <time.h>
#include <stack>
#include <array>
#include <list>
#include <atcoder/all>
#define popcount __builtin_popcount
using namespace std;
using namespace atcoder;
typedef long long ll;
typedef pair<int, int> P;

int main()
{
    int n; cin>>n;
    map<int, int> mp;
    ll c=0, c2=0, c1=0;
    for(int i=0; i<n; i++){
        int a; cin>>a;
        mp[a]++;
        if(a>=2) c++;
        else c1++;
        if(a==2) c2++;
    }
    ll ans=c*(c-1)/2+(c-c2)*c1*2+c1*c2*3+c1*(c1-1);
    cout<<ans<<endl;
    return 0;
}