x = float(input())
a = float(input())


if x < -5:
    y = a * (x) * -1 * 2
    print(round(y, 3))

elif -5 < x < 1:
    modulex = abs(x)
    y = a * modulex
    print(round(y, 3))

elif x >= 1 and (a - x != 0):
    y = 1 / (a - x)
    print(round(y, 3))
else:
    print("На ноль делить нельзя")