#include <fstream>

std::ifstream f("fractii.in");
std::ofstream g("fractii.out");

int cmmdc(int a,int b)
{
	if (a % b == 0)
		return b;
	else
		return cmmdc(b, a % b);

}

int main()
{
	int NrMax, Contor{ 0 };
	f >> NrMax;
	Contor += NrMax + NrMax - 1;
	for (int i = 2; i <= NrMax; i++)
		for (int j = i; j <= NrMax; j++)
			if (cmmdc(i, j) == 1)
				Contor+=2;
	g << Contor;
}