





def      _lowercase					(						_UpperCAmelCase				)						->  list:

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

	lowerCamelCase	 =[]

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

		generate(k - 1			,      _UpperCAmelCase				)

		for i in range(k - 1				):
			if k % 2 == 0:  # k is even
				lowerCamelCase ,  lowerCamelCase	 =arr[k - 1], arr[i]
			else:  # k is odd
				lowerCamelCase ,  lowerCamelCase	 =arr[k - 1], arr[0]
			generate(k - 1			,      _UpperCAmelCase				)

	generate(len(_UpperCAmelCase				)			,      _UpperCAmelCase				)
	return res


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












def      _lowercase					(						_UpperCAmelCase			,      _UpperCAmelCase				)						->  list[str]:
				return [sentence[i : i + ngram_size] for i in range(len(_UpperCAmelCase				) - ngram_size + 1				)]


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

							testmod()





