var n,p,q,i,j,nr:longint;
    f,g:text;
begin
assign(f,'fractii.in');reset(f);
assign(g,'fractii.out');rewrite(g);
readln(f,n);
close(f);
nr:=1;
 for i:=1 to n-1 do
  begin
   p:=i;
    for j:=i+1 to n do
     begin
      q:=j;
       while q<>p do
        if q>p then q:=q-p
         else p:=p-q;
      if p=1 then nr:=nr+1;
     end;
  end;
writeln(g,nr);
close(g);
end.