#include <bits/stdc++.h>
using namespace std;
long long int gcd(long long int a, long long int b) {
  long long int temp;
  while (b > 0) {
    temp = a;
    a = b;
    b = temp % b;
  }
  return a;
}
int main() {
  long long int x, i, j, a = 120, b;
  cin >> x;
  long long int ans = 1;
  for (i = 0; i < 5; i++) {
    ans = ans * ((x - i) * (x - i));
    long long int g = gcd(a, ans);
    ans /= g;
    a /= g;
  }
  cout << ans;
  return 0;
}
