#include<fstream>
using namespace std;

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

int main()
{

long long n,p=2,q=2,ok,i,nr;

ifstream in("fractii.in");
ofstream out("fractii.out");

in>>n;
nr=2*n-1;
while (p<=n&&n<=1000000)
{

	while (q<=n)
{
ok=cmmdc(p,q);
if (ok==1) nr++;
q++;
}


q=2;
p++;
}



out<<nr;

in.close();
out.close();
return 0;
}