#include <bits/stdc++.h>
using namespace std;

int64_t fac(int64_t n) {
  if (n <= 1) return 1;
  return fac(n - 1);
}

int main() {
  int64_t n;
  cin >> n;
  cout << fac(n + 2) / (2LL * fac(n)) << endl;
  return 0;
}