


from __future__ import annotations

from collections.abc import Iterator
from typing import Any
class      UpperCAmelCase_ :

   '''simple docstring'''




   def __init__(		self						,    __A			):






     """simple docstring"""





     lowerCamelCase			: Any   =    data
     lowerCamelCase			: Node | None   =    None






   def __str__(		self			):






     """simple docstring"""





     return F"""{self.data}"""



class      UpperCAmelCase_ :

   '''simple docstring'''




   def __init__(		self			):






     """simple docstring"""





     lowerCamelCase			: Node | None   =    None
     lowerCamelCase			: Node | None   =    None






   def __iter__(		self			):






     """simple docstring"""





     lowerCamelCase			: Optional[Any]   =    self.front
     while node:
       yield node.data
       lowerCamelCase			: Union[str, Any]   =    node.next






   def __len__(		self			):






     """simple docstring"""





     return len(tuple(iter(self			)			)			)






   def __str__(		self			):






     """simple docstring"""





     return " <- ".join(str(__A			) for item in self			)






   def _snake_case   (		self			):






     """simple docstring"""





     return len(self			) == 0






   def _snake_case   (		self						,    __A			):






     """simple docstring"""





     lowerCamelCase			: List[Any]   =    Node(__A			)
     if self.is_empty():
       lowerCamelCase			: List[Any]   =    node
     else:
       assert isinstance(self.rear						,    __A			)
       lowerCamelCase			: Tuple   =    node
       lowerCamelCase			: Dict   =    node






   def _snake_case   (		self			):






     """simple docstring"""





     if self.is_empty():
       raise IndexError("dequeue from empty queue"			)
     assert isinstance(self.front						,    __A			)
     lowerCamelCase			: str   =    self.front
     lowerCamelCase			: Dict   =    self.front.next
     if self.front is None:
       lowerCamelCase			: Union[str, Any]   =    None
     return node.data






   def _snake_case   (		self			):






     """simple docstring"""





     lowerCamelCase			: Any   =    None


if __name__ == "__main__":
   from doctest import testmod

   testmod()







def 		lowercase_(  SCREAMING_SNAKE_CASE_				,						SCREAMING_SNAKE_CASE_     ):


  '''simple docstring'''

  sequence.append(SCREAMING_SNAKE_CASE_     )

  lowerCamelCase			: str   =    0
  while sequence[index] != target:
    index += 1

  sequence.pop()

  if index == len(SCREAMING_SNAKE_CASE_     ):
    return None

  return index


if __name__ == "__main__":
   _snake_case					=					input('''Enter numbers separated by comma:\n''').strip()
   _snake_case					=					[int(item) for item in user_input.split(''',''')]

   _snake_case					=					input('''Enter a single number to be found in the list:\n''')
   _snake_case					=					int(target_input)
   _snake_case					=					sentinel_linear_search(sequence, target)
   if result is not None:
      print(f'''{target} found at positions: {result}''')
   else:
      print('''Not found''')



