text: # ネストの深いタプルを頑張って読み込んでくれる君
  
  def read(s):
      """めちゃくちゃネストの深いタプルを表す文字列 s を評価してくれる"""
      res = []
      i = 0
      cur = []
      while i < len(s):
          if s[i] == ' ' or s[i] == ',':
              i += 1
          elif s[i] == '(':
              res.append(cur)
              cur = []
              i += 1
          elif s[i] == ')':
              res[-1].append(tuple(cur))
              cur = res.pop()
              i += 1
          elif s[i] == 'N':
              cur.append(None)
              i += 4
          else:
              v = 0
              sgn = +1
              if s[i] == '-':
                  sgn = -1
                  i += 1
              while s[i].isdigit():
                  v = v * 10 + ord(s[i]) - ord('0')
                  i += 1
              cur.append(v * sgn)
      return cur[0]
  