#include<stdio.h>  
    
    int i,j,n,nr,m1,m2;  
   int cmd(int a,int b)  
   {if(b==0)return a;  
   else return cmd(b,a%b);  
   }  
   int main(void)  
  {   
  freopen("fractii.in","r",stdin);  
  freopen("fractii.out","w",stdout);  
  scanf("%d",&n);  
  m1=n;
  while(n+1-i){
  
  for(j=i+1; j<=n; j++)if(cmd(i,j)==1)nr++; i++; }
  printf("%d",2*nr+1);  
  return 0;  
  }