#include <bits/stdc++.h>
using namespace std;
 
#define lli long long int
#define REP(i,s,n) for(lli i=s;i<n;i++)
#define INF (1LL<<62)
#define DEBUG 0
#define mp(a,b) make_pair(a,b)
#define SORT(V) sort(V.begin(),V.end())
#define PI (3.141592653589794)
#define TO_STRING(VariableName) # VariableName
#define LOG(x) if(DEBUG)cout<<TO_STRING(x)<<"="<<x<<" "<<endl;
#define LOG2(x,y) if(DEBUG)cout<<TO_STRING(x)<<"="<<x<<" "<<TO_STRING(y)<<"="<<y<<endl;
#define LOG3(x,y,z) if(DEBUG)cout<<TO_STRING(x)<<"="<<x<<" "<<TO_STRING(y)<<"="<<y<<" "<<TO_STRING(z)<<"="<<z<<endl;
#define LOG4(w,x,y,z) if(DEBUG)cout<<TO_STRING(w)<<"="<<w<<" "<<TO_STRING(x)<<"="<<x<<" "<<TO_STRING(y)<<"="<<y<<" "<<TO_STRING(z)<<"="<<z<<endl;
 
template<class T>bool chmax(T & a, const T & b) { if (a < b) { a = b; return 1; } return 0; }
template<class T>bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; }

void solve(){

	lli n;
	cin>>n;
	lli d[3]={0};
	REP(i,0,n){
		lli b;
		cin>>b;
		if(b==1 || b==2)d[b]++;
		else d[0]++;
	}
	lli ans = 0;

	ans = 3*d[1]*d[2] + 2 * (d[1]*d[0] + d[1]*(d[1]-1)/2) + d[2]*d[0] + d[2]*(d[2]-1)/2 + d[0]*(d[0]-1)/2;


	cout<<ans<<endl;

}
 
int main(){
 
	ios::sync_with_stdio(false);
	std::cin.tie(nullptr);
 
	lli t = 1;
	//cin>>t;
	REP(i,0,t)solve();
 
	return 0;
}