#include<iostream>
using namespace std;
int main()
{
	int k,sum=0;
	cin >> k;
	for (int i = 1; i <= k; i++)
	{
		sum = (sum + i - 1) * 2;
	}
	cout << sum << endl;
	return 0;
}
/**************************************************************
	Problem: 1847
	User: admin
	Language: C++
	Result: Accepted
	Time:46 ms
	Memory:2072 kb
****************************************************************/