#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n;
  cin >> n;
  cout << ((n * (n - 1) * (n - 2) * (n - 3) * (n - 4)) / 120) *
              (n * (n - 1) * (n - 2) * (n - 3) * (n - 4));
}
