#include<stdio.h>
FILE *f=fopen("fractii.in","r"),*g=fopen("fractii.out","w");
long int n,fr,i,j;
long int cmmdc(long int a,long int b)
{
 long int r;
 do
 {
   r=a%b;
   a=b;
   b=r;
 }while(r);
 return a;
}
int main()
{
 fscanf(f,"%ld",&n);
 for(i=1;i<=n;i++)
   for(j=i+1;j<=n;j++)
     if(cmmdc(i,j)==1) fr++;
 fprintf(g,"%ld",fr*2+1);
}