#include <bits/stdc++.h>
using namespace std;
const int MAXN = 2e5 + 5;
long long dp[25][25], n;
long long solve(long long idx, long long num) {
  if (num == n / 2) return 1;
  if (idx == n) return 0;
  long long& ret = dp[idx][num];
  ret = 0;
  ret += solve(idx + 1, num + 1) + solve(idx + 1, num);
  return ret;
}
long long fact(long long n) {
  long long ans = 1;
  for (long long i = 1; i <= n; i++) {
    ans *= i;
  }
  return ans;
}
int main() {
  cin >> n;
  long long ans = fact(n / 2 - 1) * fact(n / 2 - 1) * solve(1, 0);
  cout << ans << endl;
  return 0;
}
