#include <fstream>

using namespace std;

ifstream r ("12perm.in");
ofstream w ("12perm.out");

unsigned long long n, factorial = 1;

int main(){

    r >> n;

    for (int i = 1; i <= n; ++i){
        factorial*=i;
    }

    if (n > 4){
        w << factorial / (n - 3);
    }
    else{
        w << factorial;
    }

    return 0;
}