#include<fstream>
using namespace std;
int main()
{
	ifstream in("fractii.in");
	ofstream out("fractii.out");
	int n,s=0,i;
	in>>n;
	for(i=1;i<=n;i++)
	{
			s=s+(n-1);
	}
	out<<s+1;
	return 0;
}