#include <stdio.h>

int cmmdc(int a,int b)
{
  int rez=0;
  while ((a!=0)&&(b!=0))
  {
    if(a>b)
      a=a%b;
    else
      b=b%a;
  }
  
  if (a==0)
    rez=b;
  else
    rez=a;
  return rez;
}

int main (int argc, const char * argv[]) {
 
  FILE *fin, *fout;
  int n;
  int count=1;
  fin=fopen("fractii.in","r");
  fout=fopen("fractii.out","w");
  fscanf(fin,"%d",&n);
   
  for(int a=1;a<=n;a++)
  {
    for(int b=1;b<=a-1;b++)
    {
      if (cmmdc(a,b)==1) 
      {
        count+=2;
        
      }
    }
  }
  
  fprintf(fout,"%d",count);
  fclose(fin);
  fclose(fout);
  return 0;
}