-- ABC 137 A
import Data.Maybe
import Data.Char
import Data.List
import qualified Data.ByteString.Char8 as BS
import qualified Data.Vector.Unboxed as VU

main :: IO ()
main = do
  [a, b] <- getIntList
  print . maximum $ [a + b, a - b, a * b]

readInt :: BS.ByteString -> Int
readInt = fst . fromJust . BS.readInt

getInt :: IO Int
getInt = readInt <$> BS.getLine

getIntList :: IO [Int]
getIntList = unfoldr (BS.readInt . BS.dropWhile isSpace) <$> BS.getLine