code: '''simple docstring'''
  
  
  
  
  
  from __future__ import annotations
  def 				__lowercase	(						lowerCamelCase__ ,				lowerCamelCase__					)				->list[int]:
  
    '''simple docstring'''
  
  
  
  
    assert len(lowerCamelCase__					) == len(lowerCamelCase__					)
  
    a__     		=     len(lowerCamelCase__					)
    a__     		=     list(range(lowerCamelCase__					)					)
    a__     		=     [-1] * n  # who the donor has donated to
    a__     		=     [-1] * n  # who the recipient has received from
    a__     		=     [0] * n
  
    while unmatched_donors:
      a__     		=     unmatched_donors[0]
      a__     		=     donor_pref[donor]
      a__     		=     donor_preference[num_donations[donor]]
      num_donations[donor] += 1
      a__     		=     recipient_pref[recipient]
      a__     		=     rec_record[recipient]
  
      if prev_donor != -1:
        if rec_preference.index(lowerCamelCase__					) > rec_preference.index(lowerCamelCase__					):
          a__     		=     donor
          a__     		=     recipient
          unmatched_donors.append(lowerCamelCase__					)
          unmatched_donors.remove(lowerCamelCase__					)
      else:
        a__     		=     donor
        a__     		=     recipient
        unmatched_donors.remove(lowerCamelCase__					)
    return donor_record
  
  
style_context: def 				__lowercase	(						lowerCamelCase__ ,				lowerCamelCase__					)				->Optional[int]:
  
    '''simple docstring'''
  
  
  
  
    sequence.append(lowerCamelCase__					)
  
    a__     		=     0
    while sequence[index] != target:
      index += 1
  
    sequence.pop()
  
    if index == len(lowerCamelCase__					):
      return None
  
    return index
  
  
  if __name__ == "__main__":
       _SCREAMING_SNAKE_CASE   						=    input("""Enter numbers separated by comma:\n""").strip()
       _SCREAMING_SNAKE_CASE   						=    [int(item) for item in user_input.split(""",""")]
  
       _SCREAMING_SNAKE_CASE   						=    input("""Enter a single number to be found in the list:\n""")
       _SCREAMING_SNAKE_CASE   						=    int(target_input)
       _SCREAMING_SNAKE_CASE   						=    sentinel_linear_search(sequence, target)
       if result is not None:
            print(F"""{target} found at positions: {result}""")
       else:
            print("""Not found""")
  
  