#include<fstream.h>
int nrd(int x)
{
   int i,j,ok,nr=0;
   for(i=x;i>=2;i--)
     {
       ok=1;
       for(j=2;j<=i;j++)
	 if(x%j==0&&i%j==0)
	   {
	     ok=0;
	     break;
	   }
       if(ok) nr+=2;
     }
   return nr;
   
}
int main()
{
   int n,i,s=0;
   ifstream f("fractii.in");
   f>>n;
   s=2*n-1;
   for(i=n;i>=3;i--)
     s+=nrd(i);
   ofstream g("fractii.out");
   g<<s;
   f.close();
   g.close();
   return 0;
}