{-# LANGUAGE TypeApplications #-}

main :: IO ()
main = do
  [p, q, r] <- map (read @Double) . words <$> getLine
  let
    s = p + q + r
    x = p / s
    y = q / s
    z = r / s
  print $ max (max (1 - x) (1 - y)) (1 - z)