import Data.List
import Data.Char
import Data.Maybe
import qualified Data.ByteString.Char8 as BS8

dig_impl 0 r = r
dig_impl n r = dig_impl (div n 10) (r + 1)

dig n = dig_impl n 0

main :: IO ()
main = do
    [a, b] <- unfoldr (BS8.readInteger . BS8.dropWhile isSpace) <$> BS8.getLine

    print $ maximum [a + b, a - b, a * b]
