#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using ul = unsigned long;

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	int n;
	cin >> n;

	ll nn{ n * 2 }, res{ 0 };

	for (ll i = 0; i < (1 << nn); ++i)
	{
		int o{ 0 }, c{ 0 };

		for (int j = 0; j < nn; ++j)
		{
			i& (1 << j) ? ++o : ++c;
			if (o < c)
				break;
		}

		if (o == c)
			++res;
	}

	cout << res << "\n";

	return 0;
}