code: 
  
  
  from __future__ import annotations
  
  
  
  
  
  
  
  class 				__SCREAMING_SNAKE_CASE   :
  
  
        def __init__(							self							,						SCREAMING_SNAKE_CASE__		):
              lowercase			:   str					   =		data
              lowercase			:   Dict					   =		None
  
  
  
  
  
  
  
  class 				__SCREAMING_SNAKE_CASE   :
  
  
        def __init__(							self		):
              lowercase			:   Optional[Any]					   =		None
  
  
        def        __lowerCamelCase			(							self							,						SCREAMING_SNAKE_CASE__		):
              lowercase			:   List[str]					   =		Node(SCREAMING_SNAKE_CASE__		)
              lowercase			:   Any					   =		self.head
              lowercase			:   List[Any]					   =		new_node
              return self.head.data
  
  
  
  
  
  
        def        __lowerCamelCase			(							self		):
              lowercase			:   Tuple					   =		self.head
              lowercase			:   List[Any]					   =		self.head
              if self.head:
                    while fast_pointer and fast_pointer.next:
                          lowercase			:   str					   =		fast_pointer.next.next
                          lowercase			:   List[str]					   =		slow_pointer.next
                    return slow_pointer.data
              else:
                    print('''No element found.'''		)
                    return None
  
  
  if __name__ == "__main__":
    __a   				=      LinkedList()
    for _ in range(int(input().strip())):
      __a   				=      int(input().strip())
      link.push(data)
    print(link.middle_element())
  
  
style_context: 
  
  
  from __future__ import annotations
  
  
  
  
  def 			__lowercase	(						_UpperCamelCase     )    ->list[int]:
  
  
  
  
  
  
  
        """simple docstring"""
  
        assert (
            isinstance(_UpperCamelCase,    _UpperCamelCase     ) and mask > 0
        ), f"""mask needs to be positive integer, your input {mask}"""
        lowercase			:   Optional[int]					   =		[]
        lowercase			:   Optional[int]					   =		mask
  
        while submask:
              all_submasks.append(_UpperCamelCase     )
              lowercase			:   Dict					   =		(submask - 1) & mask
  
        return all_submasks
  
  
  if __name__ == "__main__":
    import doctest
  
    doctest.testmod()
  
  