




'''simple docstring'''





from math import factorial


def 					UpperCamelCase_(     snake_case							:	int = 2_0					):

							'''simple docstring'''






							snake_case_      =				2 * n  # middle entry of odd rows starting at row 3 is the solution for n = 1,
							# 2, 3,...
							snake_case_      =				n // 2

							return int(factorial(snake_case					) / (factorial(snake_case					) * factorial(n - k					))					)


if __name__ == "__main__":
		import sys

		if len(sys.argv) == 1:
				print(solution(20))
		else:
				try:
						_SCREAMING_SNAKE_CASE							:       Optional[Any]						=			int(sys.argv[1])
						print(solution(n))
				except ValueError:
						print("Invalid entry - please enter a number.")










'''simple docstring'''





def 					UpperCamelCase_(     snake_case							:	list[int]							,    snake_case							:	int					):

							'''simple docstring'''






							snake_case_      =				len(snake_case					)
							snake_case_      =				[[False] * (required_sum + 1) for _ in range(arr_len + 1					)]

							# for each arr value, a sum of zero(0) can be formed by not taking any element
							# hence True/1
							for i in range(arr_len + 1					):
														snake_case_      =				True

							# sum is not zero and set is empty then false
							for i in range(1							,    required_sum + 1					):
														snake_case_      =				False

							for i in range(1							,    arr_len + 1					):
														for j in range(1							,    required_sum + 1					):
																					if arr[i - 1] > j:
																												snake_case_      =				subset[i - 1][j]
																					if arr[i - 1] <= j:
																												snake_case_      =				subset[i - 1][j] or subset[i - 1][j - arr[i - 1]]

							return subset[arr_len][required_sum]


if __name__ == "__main__":
		import doctest

		doctest.testmod()




