code: def unpack_classical_reg(c):
      
      if isinstance(c, list) or isinstance(c, tuple):
          if len(c) > 2 or len(c) == 0:
              raise ValueError("if c is a list/tuple, it should be of length <= 2")
          if len(c) == 1:
              c = (c[0], 0)
          if not isinstance(c[0], str):
              raise ValueError("if c is a list/tuple, its first member should be a string")
          if not isinstance(c[1], int):
              raise ValueError("if c is a list/tuple, its second member should be an int")
          return MemoryReference(c[0], c[1])
      if isinstance(c, MemoryReference):
          return c
      elif isinstance(c, str):
          return MemoryReference(c, 0)
      else:
          raise TypeError("c should be a list of length 2, a pair, a string, or a MemoryReference")
docs: Get the address for a classical register.
  
      :param c: A list of length 2, a pair, a string (to be interpreted as name[0]), or a MemoryReference.
      :return: The address as a MemoryReference.