(setq beer-num 99)
(setq container "bottles")

(loop while (> beer-num 0) do
      (format t "~a ~a of beer on the wall.~%" beer-num container)
      (format t "~a ~a of beer.~%" beer-num container)
      (format t "Take one down.~%")
      (format t "Pass it around.~%")

      (setq beer-num (- beer-num 1))

      (if (= beer-num 1)
        (setq container "bottle"))

      (if (> beer-num 0)
        (format t "~a ~a of beer on the wall.~%" beer-num container)
        (format t "No more of beer on the wall.~%")))