program infoarena_fractii;
  var i,j,f, n,s:int64;
    fisier:text;
function cmmdc(a,b:int64):int64;
var r:int64;
begin
  if a<b then begin a:=a+b;b:=a-b;a:=a-b;end;
   r:=a mod b;
   while r>0 do
begin
a:=b;
b:=r;
r:=a mod b;
end;
   cmmdc:=b;
end;
begin
  assign(fisier,'fractii.in');reset(fisier); read(fisier,n);close(fisier);
  s:=0;
  for i:=2 to (n-1) do
  for j:=(i+1) to n do
  if cmmdc(i,j)<>1 then s:=s+1;
  f:=n*n-2*s-(n-1);
  assign(fisier,'fractii.out');rewrite(fisier);
  write(fisier,f);close(fisier);

end.