#include <bits/stdc++.h>
using namespace std;
string s;
long long n, ans;
long long ct(long c, int t) {
  if (c < (long long)t) return 0;
  long long res = 1;
  for (int i = 0; i < t; ++i) res *= (c - (long long)i);
  for (int i = 2; i <= t; ++i) res /= (long long)i;
  return res;
}
int main() {
  cin >> n;
  ans = ct(n, 5) * ct(n, 5) * 120;
  cout << ans << endl;
  return 0;
}
