import math
X = int(input())
Y = int(input())
L = int(input())
order = 0
x = abs(X)
y = abs(Y)
if  (X != 0) and (Y > 0):
    op_x = int(math.floor(x/L))
    op_y = int(math.floor(y/L))
    order = 1
    if x >= L:
        if x == L * op_x:
            order += op_x
        elif x != L * op_x:
            order += op_x + 1
    elif x < L:
        order += 1
    if y >= L:
        if Y == L * op_y:
            order += op_y
        elif Y != L * op_y:
            order += op_y + 1
    elif y < L:
        order += 1
    print(order)

elif  (X != 0) and (Y < 0):
    op_x = int(math.floor(x/L))
    op_y = int(math.floor(y/L))
    order = 2
    if x >= L:
        if x == L * op_x:
            order += op_x
        elif x != L * op_x:
            order += op_x + 1
    elif x < L:
        order += 1
    if y >= L:    
        if y == L * op_y:
            order += op_y
        elif y != L * op_y:
            order += op_y + 1
    elif y < L:
        order += 1
    print(order)

elif (X != 0) and (Y == 0):
    op_x = int(math.floor(x/L))
    if x >= L:
        if x == L * op_x:
            order += op_x
        elif x != L * op_x:
            order += op_x + 1
    elif x < L:
        order += 1

    print(order)

else:
    op_y = int(math.floor(y / L))
    if y >= L:
        if y == L * op_y:
            order += op_y
        elif y != L * op_y:
            order += op_y + 1
    else:
        order += 1
    if Y < 0:
        order += 2
    if Y == 0:
        order = 0
    print(order)