import Text.Printf

bis ok ng f 
  | del < 1e-6 || del / ok < 1e-6 = ok
  | f m = bis m ng f
  | otherwise = bis ok m f
  where
    del = abs $ ok - ng
    m = (ok + ng) / 2

solve p q = bis 1 3.6e10 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