#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  string arr[21];
  for (int i = 0; i <= n; i++) {
    arr[i] = '0';
  }
  arr[2] = '1';
  arr[4] = '3';
  arr[6] = "40";
  arr[8] = "1260";
  arr[10] = "72576";
  arr[12] = "6652800";
  arr[14] = "889574400";
  arr[16] = "163459296000";
  arr[18] = "39520825344000";
  arr[20] = "12164510040883200";
  cout << arr[n] << endl;
}
