





import math

UpperCAmelCase__						:			Any									=10
UpperCAmelCase__						:			Optional[Any]									=7
UpperCAmelCase__						:			List[str]									=BALLS_PER_COLOUR * NUM_COLOURS





def      _lowercase					(						_UpperCAmelCase = 20				)						->  str:
				lowerCamelCase	 =math.comb(_UpperCAmelCase			,      _UpperCAmelCase				)
				lowerCamelCase	 =math.comb(NUM_BALLS - BALLS_PER_COLOUR			,      _UpperCAmelCase				)

				lowerCamelCase	 =NUM_COLOURS * (1 - missing_colour / total)

				return F"""{result:.9f}"""


if __name__ == "__main__":
							print(solution(20))












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()





