#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

int main() {
  cin.tie(nullptr)->sync_with_stdio(false);
  int n;
  cin >> n;
  int ans = 0;
  rep(bit, 1 << (2 * n)) {
    if (popcount(ull(bit)) != n) continue;
    int cur = 0;
    bool ok = true;
    rep(i, 2 * n) {
      if (bit & (1 << i))
        ++cur;
      else {
        if (cur == 0) {
          ok = false;
          break;
        }
        --cur;
      }
    }
    if (ok) ++ans;
  }
  cout << ans << '\n';
  return 0;
}