#include<fstream.h>

int cmmmdc(int a, int b)
 {
 while(a!=b)
   if(a>b) a=a-b;
      else b=b-a;
 if (a!=1) return 0;
    else return 1;}

main()
  {ifstream f("fractii.in");
  ofstream g("fractii.out");
  int n,i,j,c=0,d=0;
  f>>n;
  c=2*(n-1)+1;   
  for(i=2;i<=n;i++)
    for(j=i+1;j<=n;j++)
      if(cmmmdc(i,j)==1) d++ ;
  d=2*d;
  c=c+d    ;
  g<<c;    }