P,Q=map(int, input().split())
import math
def f(x):
  t=x**2
  s=P+Q*x*math.log(x,2)
  if t<=s:
    return True
  else:
    return False
ok=1
ng=10**10
for i in range(50):
  mid=(ok+ng)/2
  if f(mid):
    ok=mid
  else:
    ng=mid
print(ok)