#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using ld = long double;
using mint = modint998244353;

int main() {
  int N; cin >> N;
  N *= 2;
  int ans = 0;
  for (int i = 0; i < 1 << N; i++) {
    int cnt = 0;
    bool flag = true;
    for (int j = 0; j < N; j++) {
      if (i >> j & 1) {
        cnt--;
        if (cnt < 0) {
          flag = false;
          break;
        }
      } else {
        cnt++;
      }
    }
    if (flag && cnt == 0) ans++;
  }
  cout << ans << endl;
  return 0;
}