#include<fstream>
using namespace std;
ifstream fin("fractii.in");
ofstream fout("fractii.out");
long n,i,s,j,i1,j2,r;
int main()
{fin>>n;s=n+n-1;
   for(i=2;i<=n;i++)
      for(j=i+1;j<=n;j++)
       if(j%i!=0)
      {
	i1=i;j2=j;r=i1%j2;
	while(r)
	{i1=j2;
	 j2=r;
	 r=i1%j2;
	}
	if(j2==1)s+=2;

      }
fout<<s;
fin.close();
fout.close(); 
return 0;
}