#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
signed main() {
	ios::sync_with_stdio(false); cin.tie(0);
	int n;
	cin >> n;
	int ans = 0;
	for (int i = 0; i < (1 << 2 * n); i++) {
		int c = 0, cc = 0;
		for (int j = 0; j < 2 * n; j++) {
			c += (i >> j) & 1 ? 1 : -1;
			cc = min(c, cc);
			if (cc < 0) break;
		}
		ans += cc == 0 && c == 0;
	}
	cout << ans << endl;
	return 0;	
}