code: def paren_change(inputstring, opens=opens, closes=closes):
      
      count = 0
      for c in inputstring:
          if c in opens:  # open parens/brackets/braces
              count -= 1
          elif c in closes:  # close parens/brackets/braces
              count += 1
      return count
docs: Determine the parenthetical change of level (num closes - num opens).