#include<fstream.h>
gcd(long int a,long int b)
{
	if(b==0)
		return a;
	else
		return gcd(b,a%b);
}
int main()
{
	ifstream fin("fractii.in");
	ofstream fout("fractii.out");
	long int n,i,j;
	fin>>n;
	int c=0;
	for(i=1;i<=n;i++)
		for(j=i;j<=n;j++)
			if(gcd(i,j)==1)
				if(i==j)
					c++;
				else
					c=c+2;
	fout<<c<<"\n";
	return 0;
}