import strutils, sequtils, future, algorithm

var
  s=stdin.readLine
  res=0
  ng=false

for i in countdown(s.len-1, 0):
  if s[i]==')':
    ng=true
  elif s[i]=='(':
    var
      ret=s[i+1].ord-'0'.ord
      j=i+2
    while s[j]!=')':
      if s[j]=='+':
        ret+=s[j+1].ord-'0'.ord
      elif s[j]=='-':
        ret-=s[j+1].ord-'0'.ord
      j+=1
    if i-1>=0 and s[i-1]=='-':
      ret= -ret
    res+=ret
    ng=false
  if s[i].isDigit and ng==false:
    var ret=s[i].ord-'0'.ord
    if i-1>=0 and s[i-1]=='-':
      ret= -ret
    res+=ret

echo res