#include <fstream>

using namespace std;

fstream f;
fstream g;

int n;
int i,j;
long sum;
int k;
int x;
int eu(int a,int b)
{
	int r=a%b;
	while(r)
	{
		a=b;
		b=r;
		r=a%b;
	}
	return b;
}
int main()
{
    f.open("fractii.in",fstream::in);
    f >> n;
	sum=2*n-1;
	g.open("fractii.out",fstream::out);
	for(i=2;i<=n;i++)
	{
		k=1;
     if(i%2==0)
	   k++;
 		for(j=1;j<=n;j+=k)
			  if(j>1&&i!=j&&eu(i,j)==1)
				sum++;
    }
	f.close();

    
    g << sum << "\n";
    g.close();	
	
	return 0;
}