(define (read-number)
  (string->number (read-line)))

(let* ((x (read-number))
       (y (read-number))
       (l (read-number)))
  (print (+ (div (+ (- l 1) (abs x)) l)
	    (div (+ (- l 1) (abs y)) l)
	    (if (< y 0)
		2
		1))))