#include <bits/stdc++.h>
using namespace std;
int main() {
  long long ans = 0;
  long long n;
  cin >> n;
  ans += n * (n - 1) * (n - 2) * (n - 3) * (n - 4);
  ans *= n / 1 * (n - 1) / 2 * (n - 2) / 3 * (n - 3) / 4 * (n - 4) / 5;
  cout << ans;
}
