#include <bits/stdc++.h>
using namespace std;
int cnt[21];
long long binpow(int a, int power) {
  if (!power) return 1;
  int m = a;
  power--;
  while (power) {
    if (power & 1) a *= m;
    m *= m;
    power >>= 1;
  }
  return a;
}
int main() {
  int n;
  cin >> n;
  cnt[2] = 1;
  for (int i = 2; i < n; i++) {
    int x = i;
    for (int j = 2; j * j <= x; j++) {
      while (x % j == 0) {
        cnt[j]++;
        x /= j;
      }
    }
    if (x > 1) cnt[x]++;
  }
  for (int i = 2; i * i <= n; i++) {
    while (n % i == 0) {
      cnt[i]--;
      n /= i;
    }
  }
  if (n > 1) cnt[n]--;
  long long ans = 1;
  for (int i = 1; i <= 20; i++) {
    ans *= binpow(i, cnt[i]);
  }
  cout << ans;
  return 0;
}
