"""simple docstring"""






def SCREAMING_SNAKE_CASE__    (     __UpperCAmelCase				):
   if not isinstance(snake_case__ ,					snake_case__				):
      raise ValueError('''double_factorial() only accepts integral values'''				)
   if num < 0:
      raise ValueError('''double_factorial() not defined for negative values'''				)
   lowercase__:     List[str]      =   1
   for i in range(snake_case__ ,					0 ,					-2				):
      value *= i
   return value


if __name__ == "__main__":
       import doctest

       doctest.testmod()

"""simple docstring"""






def SCREAMING_SNAKE_CASE__    (     __UpperCAmelCase				)						->						int:
   if not isinstance(__UpperCAmelCase ,					__UpperCAmelCase				):
      lowercase__:     Optional[int]      =   F"""Input value of [number={number}] must be an integer"""
      raise TypeError(__UpperCAmelCase				)
   if number < 1:
      raise ValueError('''Input must be a positive integer'''				)
   return number * (2 * number - 1)


if __name__ == "__main__":
       import doctest

       doctest.testmod()
