x = int(input())
y = int(input())
l = int(input())
walk_h = 0
walk_w = 0
rotate = 0

if x == 0:
  walk_w = 0
elif x <= l:
  walk_w = 1
else:
  walk_w = abs(x // l) + abs(x % l)

if y == 0:
  walk_h = 0
elif y <= l:
  walk_h = 1
else:
  walk_h = abs(y // l) + abs(y % l)

if not x == 0:
  rotate += 1
elif x == 0 and y < 0:
  rotate += 2


print(walk_w + walk_h + rotate)