#include <stdio.h>

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

int main() 
{
 long int n,i,j,nr=0;
 FILE * fin = fopen("fractii.in","r");
 FILE * fout = fopen("fractii.out","w");

  fscanf(fin,"%ld",&n);

  for (i=2; i<n; i++)
   for (j=i+1; j<=n; j++)
    if ( cmmdc(i,j) == 1 ) nr++;
  nr = nr*2;
  nr = nr+2*n-1;

  fprintf(fout,"%ld\n",nr);
  fclose(fin);
  fclose(fout);
  return 0;
}