import Text.Printf

bis ok ng f 
  | abs (ok - ng) < 1e-9 = ok
  | f m = bis m ng f
  | otherwise = bis ok m f
  where m = (ok + ng) / 2

solve p q = bis 1 1e10 f where
  f n = n^2 <= p + q * n * logBase 2 n

main = do
  [p, q] <- map read . words <$> getLine :: IO [Double]
  printf "%.9f\n" $ solve p q