#include <iostream>
using namespace std;
long cmmdc(int a,int b)
{
	int r;
	while((r=a%b)!=0)
	{
		a=b;
		b=r;
	}
	return b;
}
int phi(int a)
{
	int i,g=0;
	for(i=1;i<=a;i++)
		if(a%i!=0&&cmmdc(a,i)==1)
			g++;
	return g+1;
}
int main()
{
	int a,m=0,i;
	//freopen("fractii.in","r",stdin);
	//freopen("fractii.out","w",stdout);
	cin>>a;
	for(i=1;i<=a;i++)
		m=m+phi(i);
	cout<<-1+2*m;
}