Codeforces_432A

// Codeforces 432A

#include <iostream>

using namespace std;

int main()
{
    int n, k, rez = 0;
    cin >> n >> k;
    int nn[n];
    for( int i = 0; i < n; i++ )
    {
        cin >> nn[i];
        if( nn[i] + k <= 5){rez++;}
    }
    cout << rez/3;
    return 0;
}