#include <iostream>
#include <map>

using namespace std;

int main()
{
    int cant, x;
    map<int,int> M;
    cout << "Cant: " << endl;
    cin >> cant;
    for(int i=0; i<cant; i++){
        cin >> x;
        M[x]++;
    }
    cout << M[4] << endl;

    return 0;
}