%  Not every program compiles ....
begin 
   read x
   /*  this is I know a silly comment but by now 
       you should have your comments right % */
       or else you may be having a problem
   /*  by the way this is also a comment */
       and this is still a comment ...
       but I think I will finish my comments now! */
   if x then x:= x+6;   % now you should complain!!!
        else x:= x-6;
   print x;
end