(let* ((counter 0)
       (path "LLR")
       (list-length (length path)))
  (tagbody
   AAA
     (if (char= (elt path (mod counter list-length)) #\L)
         (progn (incf counter) (go BBB))
         (progn (incf counter) (go CCC)))
   BBB
     (if (char= (elt path (mod counter list-length)) #\L)
         (progn (incf counter) (go DDD))
         (progn (incf counter) (go EEE)))
   CCC
     (if (char= (elt path (mod counter list-length)) #\L)
         (progn (incf counter) (go ZZZ))
         (progn (incf counter) (go GGG)))
   DDD
     (if (char= (elt path (mod counter list-length)) #\L)
         (progn (incf counter) (go DDD))
         (progn (incf counter) (go DDD)))
   EEE
     (if (char= (elt path (mod counter list-length)) #\L)
         (progn (incf counter) (go EEE))
         (progn (incf counter) (go EEE)))
   GGG
     (if (char= (elt path (mod counter list-length)) #\L)
         (progn (incf counter) (go GGG))
         (progn (incf counter) (go GGG)))
   ZZZ)
  counter)