from math import *
N1=1
N2=10**11
P,Q=map(int,input().split())
def f(x):
    return x**2-Q*x*log2(x)

while N2-N1>=10**-5:
    N=(N1+N2)/2
    if f(N)<=P:
        N1=N
    else:
        N2=N

print((N1+N2)/2)