EastWest, NorthSouth, Length = [int(input()) for _ in range(3)]
i = 0

if EastWest < 0:
    i += 1
if NorthSouth < 0:
    i += 1
L = Length

EastWest = abs(EastWest)
NorthSouth = abs(NorthSouth)

i = EastWest // Length + 1 + NorthSouth // Length + 1

print(i)