#include <bits/stdc++.h> using namespace std; long long dp[35]; int main(){ int n; while(cin>>n){ for(int i = 0;i<=n;i++) dp[i] = 0; dp[1] = 1; for(int i = 2;i<=n+1;i++){ for(int j = 1;j<=i;j++){ dp[i]+=dp[j]*dp[i-j]; } } cout<<dp[n+1]<<endl; } return 0; }