(read-line)
(read-line)

(defparameter x '())
(loop for line = (read-line nil nil) while line
    do (setq x (append x (list (parse-integer line)))))

(defvar big)
(defvar small)

(setq big (eval (append '(max) x)))
(setq small (eval (append '(min) x)))

(format 't "~d~%" (- big small))