#include <bits/stdc++.h>
using namespace std;
long long C(long long n, long long r) {
  long long up = 1, down = 1;
  for (int i = 1; i <= r; i++) down *= i;
  for (int i = n - r + 1; i <= n; i++) up *= i;
  return up / down;
}
int main() {
  vector<long long> diff = {0, 1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880};
  int n;
  scanf("%d", &n);
  printf("%lld\n", C(n, n / 2) * diff[n / 2] * diff[n / 2] / 2);
  return 0;
}
