#include <fstream>
#include <cstring>

int main()
{
	std::ifstream inputFile;
	inputFile.open("robots.in");

	int number;

	inputFile >> number;

	long int result = 0;

	while (number > 1)
	{
		number--;
		for (int i = number; i > 0; i--)
		{
			result = result + i;
		}
	}

	result = result * 12;

	std::ofstream outputFile;
	outputFile.open("robots.out");

	outputFile << result;

	return 0;
}