import Control.Applicative ((<$>), (<|>))
import Control.Monad.State
import Data.Char (isDigit, isLetter)
import Data.List (foldl', tails, inits)
import Data.Maybe (catMaybes)

main :: IO ()
main = solve <$> getLine >>= print

solve :: String -> Int
solve s = maximum . catMaybes . map (parse expr) $ zipWith (++) (tails s) (inits s)

type Parser = StateT String Maybe

parse :: Parser a -> String -> Maybe a
parse = evalStateT

anyChar :: Parser Char
anyChar = do
  s <- get
  case s of
   (x:xs) -> do
     put xs
     return x
   [] -> lift Nothing

satisfy :: (Char -> Bool) -> Parser Char
satisfy f = do
  c <- anyChar
  if f c then return c
    else lift Nothing

digit = satisfy isDigit

char c = satisfy (== c)

many :: Parser a -> Parser [a]
many p = (:) <$> p <*> many p <|> return []

many1 :: Parser a -> Parser [a]
many1 p = (:) <$> p <*> many p

eof :: Parser ()
eof = do
  s <- get
  case s of
   [] -> lift $ Just ()
   _  -> lift Nothing

expr :: Parser Int
expr = do
  x <- num
  fs <- many (plus <|> minus)
  eof
  return $ foldl' (\a f -> f a) x fs

num :: Parser Int
num = read <$> many1 digit

plus :: Parser (Int -> Int)
plus = do
  char '+'
  x <- num
  return (+x)

minus :: Parser (Int -> Int)
minus = do
  char '-'
  x <- num
  return (subtract x)