#include<stdio.h>
int n;
FILE *f=fopen("fractii.in","r");
FILE *g=fopen("fractii.out","w");
int cmc(int a,int b)
{int c;
 if(a<b) {c=a;a=b;b=c;}
 while(b)
 {c=a%b;
  a=b;
  b=c;}
 return a;}
int main()
{int i,j,nr=0;
 fscanf(f,"%d",&n);
 for(i=1;i<=n-1;i++)
  for(j=i+1;j<=n;j++)
    if(cmc(i,j)==1) nr++;
 nr=2*nr +1; 
 fprintf(g,"%d",nr);
 return 0;}