module Main where

import Control.Monad

rotate :: Int -> Int -> Int
rotate 0 y
    | y >= 0 = 0
rotate x y
    | y >= 0    = 1
    | otherwise = 2

move :: Int -> Int -> Int
move _  0 = 0
move dt n
    | r == 0    = q
    | otherwise = q + 1
  where
    (q, r) = (abs n) `divMod` dt

main :: IO ()
main = do
    x  <- readLn :: IO Int
    y  <- readLn
    dt <- readLn
    print $ rotate x y + move dt x + move dt y