#include <bits/stdc++.h> #define int long long using namespace std; int f[1005] = {1,1}; int n; signed main() { for (int i = 2; i <= 25; i++) for (int j = 0; j < i; j++) f[i] += f[j] * f[i - 1 - j]; while (cin >> n) cout << f[n] << endl; return 0; }