





'''simple docstring'''




def 	__lowerCamelCase			(      __lowerCAmelCase       :							list		)		->  list:

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

   snake_case 						=   []

   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
            snake_case						,    snake_case 						=   arr[k - 1], arr[i]
         else:  # k is odd
            snake_case						,    snake_case 						=   arr[k - 1], arr[0]
         generate(k - 1      ,    __lowerCAmelCase		)

   generate(len(__lowerCAmelCase		)      ,    __lowerCAmelCase		)
   return res


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








'''simple docstring'''




def 	__lowerCamelCase			(      __lowerCAmelCase       :							int		)		->  int:
   assert isinstance(__lowerCAmelCase      ,    __lowerCAmelCase		), F'''The input value of [n={number}] is not an integer'''

   if number == 1:
      return 2
   elif number < 1:
      snake_case 						=   F'''The input value of [n={number}] has to be > 0'''
      raise ValueError(__lowerCAmelCase		)
   else:
      snake_case 						=   sylvester(number - 1		)
      snake_case 						=   num - 1
      snake_case 						=   num
      return lower * upper + 1


if __name__ == "__main__":
 print(F"""The 8th number in Sylvester's sequence: {sylvester(8)}""")

