import sequtils, strutils

const
  ts = {
    "++":" p ",
    "+-":" m ",
    "-+":" m ",
    "--":" p ",
    "+" :" p ",
    "-" :" m ",
  }

let
  xopy = stdin.readLine
var
  seq1 = xopy.multiReplace(ts).split

if seq1[0] == "":
  seq1 = seq1[1..^1]
if seq1[0] == "m":
  seq1[1] = "-" & seq1[1]
if seq1[0] in @["p", "m"]:
  seq1 = seq1[1..^1]

let
  x = seq1[0].parseInt
  op = seq1[1]
  y = seq1[2].parseInt

echo:
  if op == "p": x - y
  else: x + y