import math

def f(x):
    return x**2 - q*x*math.log2(x) - p

def bisect_search(l, r):
    m = 1
    for i in range(10**5):
        m = (r+l)/2
        if f(m) > 0:
            r = m
        else:
            l = m
    return m

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

print(bisect_search(1, 10**18))