#include <bits/stdc++.h>
using namespace std;
const long long int N = 100005;
long long int factorial(long long int n) {
  if (n == 1) {
    return 1;
  }
  long long int ans = n * factorial(n - 1);
  return ans;
}
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  {
    long long int i, j, k, n, m, ans = 1, cnt = 0, sum = 0;
    cin >> n;
    for (long long int i = (long long int)(0); i < (long long int)(5); i++) {
      ans *= (n - i);
    }
    ans /= factorial(5);
    for (long long int i = (long long int)(0); i < (long long int)(5); i++) {
      ans *= (n - i);
    }
    cout << ans << endl;
  }
}
