(defun challenge-5()
  "Solves 5.th challenge by loading 400 webpages.

   Last page is:  peak.html  "
  (let
   ((orig-url "http://www.pythonchallenge.com/pc/def/linkedlist.php?nothing=")
    (newval 12345) (oldval 12345) (myreg "(?<=next nothing is )\\d+"))
  (loop for x from 1 to 400 do
       (setf newval (http-request (format nil "~a~d" orig-url oldval)))
       (if (not (scan-regex "html" newval))
                (format t "~d:~10t~a~%" x newval)
                (return-from challenge-5 newval))
       (if (not (scan-regex "Divide" newval))
           (setf oldval (scan-regex "(?<=next nothing is )\\d+" newval))
           (setf oldval (/ (parse-integer oldval) 2)))
       (format t "~d:~10t~a~%" x oldval))))