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