#include <bits/stdc++.h>
using namespace std;
long long ans = 0, n, c = 1;
void rec(int pos, int col, vector<bool> b) {
  if (pos == n + 1) {
    if (col == n / 2) {
      ans++;
    }
    return;
  }
  rec(pos + 1, col, b);
  if (col < n / 2) {
    b[pos] = 1;
    rec(pos + 1, col + 1, b);
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin >> n;
  vector<bool> b(n + 1);
  rec(1, 0, b);
  for (int i = 2; i < n / 2; i++) {
    c *= i;
  }
  cout << ans / 2 * c * c;
}
