(setq mazeList '(A A A B B B C C C))
(print mazeList)
(nsubstitute 'F 'a mazeList)
(nsubstitute 'L 'b mazeList)
(nsubstitute 'R 'c mazeList)
(print mazeList)
 
(defun my-compress (mazeList start end)
 
       (let ( (a-string "" ))
       (do ((i start (+ i 1)))
           ((> i end) a-string)
         (setf a-string (concatenate 'string  a-string (string  (nth i
a-list) ))))))