code: def flatten_(structure):
    if isinstance(structure, dict):
      if structure:
        structure = zip(*sorted(structure.items(), key=lambda x: x[0]))[1]
      else:
        structure = ()
    if isinstance(structure, (tuple, list)):
      result = []
      for element in structure:
        result += flatten_(element)
      return tuple(result)
    return (structure,)