from math import log2
p,q = map(int,input().split())
def f(n) :
    return q*n*log2(n) >=n*n-p
top = 10**11
bot = 1
while top - bot > 0.00001:
    mid = (top + bot)/2
    if f(mid):bot = mid
    else:top = mid
print(bot)