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

using Int = long long;
const char newl = '\n';

template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}
template<typename T> void drop(const T &x){cout<<x<<endl;exit(0);}
template<typename T=Int>
vector<T> read(size_t n){
  vector<T> ts(n);
  for(size_t i=0;i<n;i++) cin>>ts[i];
  return ts;
}

//INSERT ABOVE HERE
signed main(){
  cin.tie(0);
  ios::sync_with_stdio(0);

  Int n;
  cin>>n;
  auto as=read(n);

  Int one=count(as.begin(),as.end(),1);
  Int two=count(as.begin(),as.end(),2);

  Int ans=0;
  // three: one, two
  ans+=3*one*two;
  // one: not one
  ans+=1*(n-one)*(n-one-1)/2;
  // two: others
  ans+=2*(n*(n-1)/2-one*two-(n-one)*(n-one-1)/2);
  cout<<ans<<newl;
  return 0;
}