#include <bits/stdc++.h>
using namespace std;
long long n, nn;
long long c[22][22], jc[22];
signed main() {
  nn = 20;
  for (long long i = 1; i <= nn; i++) c[i][0] = c[i][i] = 1;
  for (long long i = 1; i <= nn; i++)
    for (long long j = 1; j <= nn; j++) c[i][j] = c[i - 1][j - 1] + c[i - 1][j];
  jc[0] = 1;
  for (long long i = 1; i <= nn; i++) jc[i] = jc[i - 1] * i;
  cin >> n;
  long long ans = c[n][n / 2] * jc[n / 2 - 1] * jc[n / 2 - 1];
  cout << ans << endl;
  return 0;
}
