import numpy as np

p, q = map(int, input().split())

ok = 1
ng = 10 ** 8


# def hantei(a):
#     takahashi = pow(2, (a * a - p))
#     hikuhashi = pow(2, (q * a)) * a
#     return takahashi <= hikuhashi


def hantei2(a):
    takahashi = a * a
    hikuhashi = p + q * a * np.log2(a)
    return takahashi <= hikuhashi


while not hantei2(ng):
    ng *= 10
while ng - ok > 10 ** (-7):
    mid = (ok + ng) / 2
    if hantei2(mid):
        ok = mid
    else:
        ng = mid
print(ok)