#include <bits/stdc++.h>
using namespace std;
int main(){
  cout << fixed << setprecision(20);
  int N;
  cin >> N;
  if (N <= 4){
    cout << 0 << endl;
  } else {
    vector<double> fact(100);
    fact[0] = 1;
    for (int i = 1; i <= 99; i++){
      fact[i] = fact[i - 1] * i;
    }
    double a = fact[99] / (fact[5] * fact[94]);
    double b = fact[N] / (fact[5] * fact[N - 5]);
    cout << b / a * 12 << endl;
  }
}