var n,x,a,b,r,i,k:longint;
    f,ff:text;
begin
 assign(f,'fractii.in');reset(f);
 assign(ff,'fractii.out');rewrite(ff);
 read(f,n);
 for i:=1 to n-1 do
  for k:=i+1 to n do
   begin
    a:=k;
    b:=i;
    r:= k mod i;
    while r<>0 do
     begin
      a:=b;
      b:=r;
      r:=a mod b;
    end;
   if b=1 then
    inc(x,2);
   end;
 inc(x);
 write(ff,x);
 close(f);
 close(ff);
end.