// jardakovezes haromfele elemmel.cpp : This file contains the 'main' function. Program execution begins and ends there.
//

#include <iostream>
#include <vector>

using namespace std;

int i, n, j;

int main()
{
	cin >> n;
	vector <long long> dp(n + 1);

	dp[0] = 1;
	dp[1] = 2;
	dp[2] = 11;
	for (i = 3; i <= n; ++i)
	{
		dp[i] = 2 * dp[i - 2] + 7 * dp[i - 1];
		for (j = i - 3; j >= 0; --j)
		{
			dp[i] += dp[j] * 7;
		}

		for (j = i - 4; j >= 0; --j)
		{
			dp[i] += dp[j] * 6;
		}
	}

	cout << dp[n];
}

// Run program: Ctrl + F5 or Debug > Start Without Debugging menu
// Debug program: F5 or Debug > Start Debugging menu

// Tips for Getting Started: 
//   1. Use the Solution Explorer window to add/manage files
//   2. Use the Team Explorer window to connect to source control
//   3. Use the Output window to see build output and other messages
//   4. Use the Error List window to view errors
//   5. Go to Project > Add New Item to create new code files, or Project > Add Existing Item to add existing code files to the project
//   6. In the future, to open this project again, go to File > Open > Project and select the .sln file