#include<fstream>

using namespace std;

int Cmmdc(int a,int b)
{
	int r=1;
	while(r!=0)
	{
		r=a%b;
		a=b;
		b=r;
	}
	return a;
}

int main()
{
	ifstream fin ("fractii.in");
	ofstream fout ("fractii.out");
	
	long nr=0;
	int i,j,n;
	fin>>n;
	for (i=1;i<=n;i++)
		for (j=i+1;j<=n;j++)
			if (Cmmdc(i,j)==1) nr++;
	fout<<2*nr+1<<"\n";
	return 0;
}