


from math import factorial






def 							_lowercase    (		SCREAMING_SNAKE_CASE_   :		List[str]       ,  SCREAMING_SNAKE_CASE_   :		List[Any]	):





			"""simple docstring"""




			if n < k or k < 0:
						raise ValueError("""Please enter positive integers for n and k where n >= k"""	)
			return factorial(_snake_case	) // (factorial(_snake_case	) * factorial(n - k	))


if __name__ == "__main__":
				print(
				    "The number of five-card hands possible from a standard",
				    F'''fifty-two card deck is: {combinations(52, 5)}\n''',
				)

				print(
				    "If a class of 40 students must be arranged into groups of",
				    F'''4 for group projects, there are {combinations(40, 4)} ways''',
				    "to arrange them.\n",
				)

				print(
				    "If 10 teams are competing in a Formula One race, there",
				    F'''are {combinations(10, 3)} ways that first, second and''',
				    "third place can be awarded.",
				)








def 							_lowercase    (		SCREAMING_SNAKE_CASE_   :		int	):





			"""simple docstring"""




			assert (
			    isinstance(SCREAMING_SNAKE_CASE_       ,  SCREAMING_SNAKE_CASE_	) and number_of_steps > 0
			), f'number_of_steps needs to be positive integer, your input {number_of_steps}'
			if number_of_steps == 1:
						return 1
			UpperCamelCase  ,  UpperCamelCase         =					1, 1
			for _ in range(number_of_steps - 1	):
						UpperCamelCase  ,  UpperCamelCase         =					current + previous, current
			return current


if __name__ == "__main__":
			import doctest

			doctest.testmod()




