#include <bits/stdc++.h>
using namespace std;
#define Catalan 20
#define LL long long
LL f[Catalan];
int n;

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