(defvar X)
(defvar Y)
(defvar L)
(setq X (parse-integer (read-line)))
(setq Y (parse-integer (read-line)))
(setq L (parse-integer (read-line)))


(defparameter o 0)

(if (and (= Y 0) (= X 0))  (setq o 0))
(if (and (= Y 0) (/= X 0)) (setq o 1))

(if (and (> Y 0) (= X 0)) (setq o 0))
(if (and (> Y 0) (/= X 0)) (setq o 1))

(if (and (< Y 0) (= X 0)) (setq o 2))
(if (and (< Y 0) (/= X 0)) (setq o 2))

;(format 't "o=<~d>~%" o)

(if (/= X 0) (setq o (+ o (ceiling (abs X) L))))
(if (/= Y 0) (setq o (+ o (ceiling (abs Y) L))))

;(format 't "o=<~d>~%" o)
(format 't "~d~%" o)