#include <iostream>
using namespace std;
int n, a[20] = {1, 1};
int main() {
	cin >> n;
	for (int i = 2; i <= n; i++) {
		for (int j = 0; j <= i - 1; j++) {
			a[i] += a[j] * a[i - j - 1];
        }
    }
	cout << a[n];
	return 0; 
}