X = int(input('X'))
Y = int(input('Y'))
L = int(input('L'))
x = y = 0
count = count_x = count_y = 0

if X < 0:
    x = X * (-1)
else:
    x = X
if Y < 0:
    y = Y * (-1)
else:
    y = Y

if x > L:
    count_x = x // L
    if x % L > 0:
        count_x += 1
elif x == 0:
    count_x = 0
else:
    count_x += 1

if X < 0:
    count_x += 1

if y > L:
    count_y = y // L
    if y % L > 0:
        count_y += 1
elif y == 0:
    count_y = 0
else:
    count_y += 1

if Y < 0:
    count_y += 1

print(count_x + count_y)