#include <stdio.h>
int cmmdc(long a, long b)
 {
  register int r;
  do
   {
    r=a%b;
    a=b;
    b=r;
   }
  while (b!=0);
  if (a==1)
     return 1;
  return 0;
 }
int main()
 {
  long n;
  freopen ("fractii.in","r",stdin);
  freopen ("fractii.out","w",stdout);

  scanf("%ld",&n);
  long nr=1;

  for (register int i=1;i<=n-1;i++)
      for (register int j=i+1;j<=n;j++)
	  {
	   if (cmmdc(i,j))
	      nr+=2;
	  }
  printf("ld\n",nr);
  fclose(stdout);
  return 0;
 }