#include <bits/stdc++.h>
using namespace std;
const int mod = 1e9 + 7;
const long long inf = 1e18;
const double eps = 1e-13;
const int N = 5e5 + 5;
long long C(long long n, long long m) {
  long long res = 1;
  for (int i = 1; i <= m; ++i) {
    res = (res * (n - i + 1)) / i;
  }
  return res;
}
int main() {
  long long n;
  cin >> n;
  long long ans = 1;
  for (int i = 1; i <= 5; ++i) {
    ans = ((ans * (n - i + 1)) / i) * (n - i + 1);
  }
  cout << ans << endl;
  return 0;
}
