import math def f(x): return x ** 2 - p - q * x * math.log2(x) p, q = map(int, input().split()) i = 0 left = 0 right = 10 ** 15 half = right / 2 eps = 10 ** (-7) while True: diff = f(half) if abs(diff) < eps: break elif diff > 0: right = half half = (left + right) / 2 else: left = half half = (left + right) / 2 print(half)