#include <algorithm>
#include <bitset>
#include <cassert>
#include <cmath>
#include <cstdio>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <unordered_set>
using namespace std;
#if __has_include(<atcoder/all>)
#include <atcoder/all>
using namespace atcoder;
#endif
#define GET_MACRO(_1, _2, _3, NAME, ...) NAME
#define _rep(i, n) _rep2(i, 0, n)
#define _rep2(i, a, b) for(int i = (int)(a); i < (int)(b); i++)
#define rep(...) GET_MACRO(__VA_ARGS__, _rep2, _rep)(__VA_ARGS__)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
using i64 = long long;
template<class T, class U>
bool chmin(T& a, const U& b) { return (b < a) ? (a = b, true) : false; }
template<class T, class U>
bool chmax(T& a, const U& b) { return (b > a) ? (a = b, true) : false; }

template<typename T>istream& operator>>(istream&i,vector<T>&v){rep(j,v.size())i>>v[j];return i;}
template<typename T>string join(vector<T>&v){stringstream s;rep(i,v.size())s<<' '<<v[i];return s.str().substr(1);}
template<typename T>ostream& operator<<(ostream&o,vector<T>&v){if(v.size())o<<join(v);return o;}
template<typename T>string join(vector<vector<T>>&vv){string s="\n";rep(i,vv.size())s+=join(vv[i])+"\n";return s;}
template<typename T>ostream& operator<<(ostream&o,vector<vector<T>>&vv){if(vv.size())o<<join(vv);return o;}

int main()
{
    int n;
    cin >> n;
    vector<int> a(n);
    cin >> a;
    map<int, i64> mp;
    rep(i, n)
    {
        if (a[i] == 1) mp[1]++;
        else if (a[i] == 2) mp[2]++;
        else mp[3]++;
    }
    i64 ans = 0;
    ans += mp[1] * (mp[1] - 1);
    ans += mp[1] * mp[2] * 3;
    ans += mp[2] * (mp[2] - 1) / 2;
    ans += mp[3] * mp[2];
    ans += mp[3] * (mp[3] - 1) / 2;
    ans += mp[1] * mp[3] * 2;
    cout << ans << endl;
}