{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE BangPatterns #-}

import Control.Applicative
import Control.Monad
import Control.Arrow
import Data.List
import Data.Maybe
import Data.Char
import Text.Printf

readInt = ( readLn :: IO Int )
getInts = map ( read :: String -> Int ) . words <$> getLine

which a b f = if f then a else b
mp [ a, b ] = ( a, b )

main = do
	[ b, c ] :: [ Double ] <- sort . map read . words <$> getLine
	printf "%.12f\n" $ if b == c
		then sqrt $ b^2 + c^2
		else sqrt $ c^2 - b^2