(let* ((rep_ (lambda (rep_ n x)
             (if (= n 0)
                 ""
                 (concat (rep_ rep_ (- n 1) x) x))))
       (rep (rep_ rep_))
       (rep200 (rep 200))
       (R200 (rep200 "R"))
       (L200 (rep200 "L"))
       (left (rep200 (concat R200 L200 "D")))
       (right (rep200 (concat L200 R200 "U"))))
  (concat
   "solve lambdaman21 "
   R200
   (rep 76 "D")
   right
   left
   (rep 93 "U")
   (rep200 "RD")
   right
   L200
   (rep 23 "U")
   (rep200 "RU")
   left
   right
   (rep 95 "D")
   L200
   (rep200 "U")
   left))