

'''simple docstring'''

from __future__ import annotations

from typing import Generic, TypeVar

lowercase__            =     TypeVar("T")




class 			A_					(							Generic[T]				):






     '''simple docstring'''



     def __init__(						self					:	Dict	,     lowercase_					:	T			)		->      Optional[Any]:
      UpperCAmelCase			:      Union[str, Any]		   =					data  # Assign data
      UpperCAmelCase			:      str		   =					None  # Initialize next as null
      UpperCAmelCase			:      Optional[int]		   =					None  # Initialize prev as null




class 			A_					(							Generic[T]				):






     '''simple docstring'''



     def __init__(						self					:	Tuple			)		->      None:
      UpperCAmelCase			:      Optional[Any]		   =					None


     def   UpperCAmelCase_			(						self					:	int	,     lowercase_					:	T			)		->      None:




      if self.head is None:
       UpperCAmelCase			:      List[str]		   =					Node(__lowerCamelCase			)
      else:
       UpperCAmelCase			:      str		   =					Node(__lowerCamelCase			)
       UpperCAmelCase			:      List[Any]		   =					new_node
       UpperCAmelCase			:      Dict		   =					self.head
       UpperCAmelCase			:      Tuple		   =					None
       UpperCAmelCase			:      Optional[Any]		   =					new_node


     def   UpperCAmelCase_			(						self					:	List[str]			)		->      T | None:




      if self.head is None:
       return None
      else:
       assert self.head is not None
       UpperCAmelCase			:      int		   =					self.head.data
       UpperCAmelCase			:      Any		   =					self.head.next
       if self.head is not None:
        UpperCAmelCase			:      List[str]		   =					None
       return temp


     def   UpperCAmelCase_			(						self					:	List[str]			)		->      T | None:
      return self.head.data if self.head is not None else None


     def __len__(						self					:	Optional[Any]			)		->      int:
      UpperCAmelCase			:      str		   =					self.head
      UpperCAmelCase			:      Any		   =					0
      while temp is not None:
       count += 1
       UpperCAmelCase			:      int		   =					temp.next
      return count


     def   UpperCAmelCase_			(						self					:	Tuple			)		->      bool:
      return self.head is None




     def   UpperCAmelCase_			(						self					:	int			)		->      None:
      print('stack elements are:'			)
      UpperCAmelCase			:      Optional[int]		   =					self.head
      while temp is not None:
       print(temp.data	,     end='->'			)
       UpperCAmelCase			:      Tuple		   =					temp.next


# Code execution starts here
if __name__ == "__main__":
 # Start with the empty stack
 lowercase__            =     Stack()

 # Insert 4 at the beginning. So stack becomes 4->None
 print("Stack operations using Doubly LinkedList")
 stack.push(4)

 # Insert 5 at the beginning. So stack becomes 4->5->None
 stack.push(5)

 # Insert 6 at the beginning. So stack becomes 4->5->6->None
 stack.push(6)

 # Insert 7 at the beginning. So stack becomes 4->5->6->7->None
 stack.push(7)

 # Print the stack
 stack.print_stack()

 # Print the top element
 print("\nTop element is ", stack.top())

 # Print the stack size
 print("Size of the stack is ", len(stack))

 # pop the top element
 stack.pop()

 # pop the top element
 stack.pop()

 # two elements have now been popped off
 stack.print_stack()

 # Print True if the stack is empty else False
 print("\nstack is empty:", stack.is_empty())












'''simple docstring'''





def  lowerCamelCase_  (     lowercase__):
 return int(lowercase__) if x - int(lowercase__) <= 0 else int(lowercase__) + 1


if __name__ == "__main__":
 import doctest

 doctest.testmod()

