#include <iostream>
using namespace std;


int main(){
	int n;
	cin>>n;
	int f[n+1];
	f[0] = 1;
	f[1] = 1;
	for(int i=2;i<=n;i++){
		f[i] = 0;
		for(int j=0;j<i;j++){
			f[i] += f[j]*f[i-j-1];
		}
	}
	
	
	cout<<f[n];
	return 0;
}