
def        __UpperCamelCase					(    lowerCAmelCase__							:    list  ):

 if len(lowerCAmelCase__  ) <= 1:
  return [tuple(lowerCAmelCase__  )]

 __a			:  List[Any]		    =  []

 def generate(lowerCAmelCase__							:    int  ,       lowerCAmelCase__							:    list  ):
  if k == 1:
   res.append(tuple(arr[:]  )  )
   return

  generate(k - 1  ,       lowerCAmelCase__  )

  for i in range(k - 1  ):
   if k % 2 == 0:  # k is even
    __a    ,	__a			:  Optional[int]		    =  arr[k - 1], arr[i]
   else:  # k is odd
    __a    ,	__a			:  Tuple		    =  arr[k - 1], arr[0]
   generate(k - 1  ,       lowerCAmelCase__  )

 generate(len(lowerCAmelCase__  )  ,       lowerCAmelCase__  )
 return res


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


from transformers import BertTokenizerFast

from .custom_tokenization import CustomTokenizer



class 		UpperCamelCase__  (	__lowercase   ):
   _SCREAMING_SNAKE_CASE				:							Union[str, Any]     	=				CustomTokenizer
   pass
