fun readStr () =
    let
        fun scan reader stream = SOME (StringCvt.splitl (not o Char.isSpace) reader (StringCvt.skipWS reader stream))
    in
        valOf (TextIO.scanStream scan TextIO.stdIn)
    end

fun intString n =
    if 0 <= n
    then Int.toString n
    else "-" ^ Int.toString (abs n)

fun findOpIndex i (#"+" :: _) = i
  | findOpIndex i (#"-" :: _) = i
  | findOpIndex i (_ :: rest) = 
    findOpIndex (i + 1) rest

val () =
    let
        val s = readStr ()

        val opIndex = findOpIndex 1 (List.tl (String.explode s))

        val x = valOf (Int.fromString (String.substring (s, 0, opIndex)))
        val y = valOf (Int.fromString (String.extract (s, opIndex + 1, NONE)))

        val opChar = String.sub (s, opIndex)

        val ans = if opChar = #"+" then x - y
                  else x + y
    in
        print (intString ans ^ "\n")
    end