sides = 0
rolls = 0

maxV = 0
counter = 0

while True:
    value = input("Enter your roll here ([Rolls]d[Sides]):  ")
    rolls, sides = value.split('d')
    sides, rolls = int(sides), int(rolls)

    for counter in range(1,sides+1):
        maxV += counter*(((counter/sides)**rolls) - (((counter-1)/sides)**rolls))

    print(round(maxV,2))
    maxV = 0