





def   a_    ( lowerCAmelCase_      :			str,	lowerCAmelCase_      :			list[str]	):
   __lowerCAmelCase								=	''
   for word_or_phrase in separated:
      if not isinstance(lowerCAmelCase_,	lowerCAmelCase_	):
         raise Exception('join() accepts only strings to be joined'	)
      joined += word_or_phrase + separator
   return joined.strip(lowerCAmelCase_	)


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

     testmod()








def   a_    ( lowerCAmelCase_      :			int	):
   if number < 0:
      raise ValueError('number must not be negative'	)
   return number & (number - 1) == 0


if __name__ == "__main__":
     import doctest

     doctest.testmod()

