import math
log = math.log

P, Q = map(int, input().split())

def f(x):
    return x*x - Q * x * log(x, 2) - P
def dfdx(x):
    return 2*x - Q*(log(x, 2) + 1 / log(2))
    
x0 = 1e11
for i in range(1000):
    if dfdx(x0) == 0:
        x0 -= 1e-5
    else:
        x0 = x0 - f(x0) / dfdx(x0)
print(x0)