code: 
  
  
  from __future__ import annotations
  
  from collections.abc import Iterator
  from typing import Any
  
  
  
  
  
  class 					snake_case__  :
  
  
  
  
  
  	def __init__(  self				,    UpperCamelCase_							)		->			None:
  								"""simple docstring"""
  
  
  
  
  
  
  								a_       :   Any			=	data
  								a_       :   Node | None			=	None
  
  
  
  
  
  	def __str__(  self							)		->			str:
  								"""simple docstring"""
  
  
  
  
  
  
  								return f"""{self.data}"""
  
  
  
  
  
  class 					snake_case__  :
  
  
  
  
  
  	def __init__(  self							)		->			None:
  								"""simple docstring"""
  
  
  
  
  
  
  								a_       :   Node | None			=	None
  								a_       :   Node | None			=	None
  
  
  
  
  
  	def __iter__(  self							)		->			Iterator[Any]:
  								"""simple docstring"""
  
  
  
  
  
  
  								a_       :   Optional[int]			=	self.front
  								while node:
  															yield node.data
  															a_       :   Tuple			=	node.next
  
  
  
  
  
  	def __len__(  self							)		->			int:
  								"""simple docstring"""
  
  
  
  
  
  
  								return len(tuple(iter(self							)							)							)
  
  
  
  
  
  	def __str__(  self							)		->			str:
  								"""simple docstring"""
  
  
  
  
  
  
  								return " <- ".join(str(UpperCamelCase_							) for item in self							)
  
  
  
  
  
  	def     A				(  self							)		->			bool:
  								"""simple docstring"""
  
  
  
  
  
  
  								return len(self							) == 0
  
  
  
  
  
  	def     A				(  self				,    UpperCamelCase_							)		->			None:
  								"""simple docstring"""
  
  
  
  
  
  
  								a_       :   Union[str, Any]			=	Node(UpperCamelCase_							)
  								if self.is_empty():
  															a_       :   Tuple			=	node
  								else:
  															assert isinstance(self.rear				,    UpperCamelCase_							)
  															a_       :   str			=	node
  															a_       :   Any			=	node
  
  
  
  
  
  	def     A				(  self							)		->			Any:
  								"""simple docstring"""
  
  
  
  
  
  
  								if self.is_empty():
  															raise IndexError("""dequeue from empty queue"""							)
  								assert isinstance(self.front				,    UpperCamelCase_							)
  								a_       :   List[Any]			=	self.front
  								a_       :   Tuple			=	self.front.next
  								if self.front is None:
  															a_       :   Dict			=	None
  								return node.data
  
  
  
  
  
  	def     A				(  self							)		->			None:
  								"""simple docstring"""
  
  
  
  
  
  
  								a_       :   int			=	None
  
  
  if __name__ == "__main__":
  	from doctest import testmod
  
  	testmod()
  
  
  
style_context: 
  
  
  def 						_lowerCamelCase		(							SCREAMING_SNAKE_CASE_				: list[int]      ):
  
  
  
  
  
  
  							"""simple docstring"""
  
  
  
  							a_       :   List[Any]			=	len(SCREAMING_SNAKE_CASE_      )
  							if n in (0, 1):
  														return 0
  							return sum(query * (n - i - 1) for i, query in enumerate(sorted(SCREAMING_SNAKE_CASE_      )      )      )
  
  
  if __name__ == "__main__":
  	import doctest
  
  	doctest.testmod()
  
  
  