#include<fstream.h>
int cmmdc(long a, long b)
{
 while(a!=b)
  if(a>b)
	a-=b;
  else
	b-=a;
 return a;
}
long int n,i,j,nr=0;
int main()
{
 ifstream f("fractii.in");
 ofstream g("fractii.out");


 f>>n;
// if(!n%2)
 {
  for(i=1;i<=n;i++)
  {
	for(j=i+1;j<=n;j++)
	{
	 if(i%2==0 && j%2==0)
	  j++;
	 if(cmmdc(i,j)==1)
	  nr+=2;
	}
  }
 }
/* else
 {
  for(i=1;i<=n/2+1;i++)
	for(j=1;j<=n;j++)
	 if(cmmdc(i,j)==1)
	  nr+=2;
 }*/
 g<<nr+1;
 f.close();
 g.close();
 return 0;

}