var
 i,j,n,c:longint;
procedure citire;
var
 f:text;
begin
 assign(f,'fractii.in');
 reset(f);
 readln(f,n);
 close(f);
end;
procedure gaselnita;
var
 f:text;
begin
 c:=0;
 for i:=1 to n do
  for J:=1 to n do
   if (i mod j <>j div 2) or (i div j=i)
    then
     c:=c+1;
 assign(f,'fractii.out');
 rewrite(f);
 writeln(f,c);
 close(f);
end;
begin
 citire;
 gaselnita;
end.