main::IO()
main = do
  x:xs <-getLine
  let as = takeWhile (`elem` ['0'..'9']) xs
      (f:cs) = drop (length as) xs
      exe (v:vs)
        |v=='+'    = vs
        |otherwise = v:vs
      sgn '+' = -1
      sgn _   =  1

  print $ (read $exe (x:as)) + sgn f * (read $exe cs)