


'''simple docstring'''
from math import factorial


def       a				(      __a = 20       )  ->     int:



					'''simple docstring'''






					UpperCamelCase__       :Dict							 =			2 * n  # middle entry of odd rows starting at row 3 is the solution for n = 1,
					# 2, 3,...
					UpperCamelCase__       :List[Any]							 =			n // 2

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


if __name__ == "__main__":
		import sys

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



'''simple docstring'''
import socket


def       a				(      )  ->     Dict:



					'''simple docstring'''






					UpperCamelCase__       :int							 =			socket.socket(socket.AF_INET			, socket.SOCK_STREAM       )
					UpperCamelCase__       :List[Any]							 =			socket.gethostname()
					UpperCamelCase__       :List[str]							 =			12312

					sock.connect((host, port)       )
					sock.send(B'''Hello server!'''       )

					with open('''Received_file'''			, '''wb'''       ) as out_file:
										print('''File opened'''       )
										print('''Receiving data...'''       )
										while True:
															UpperCamelCase__       :str							 =			sock.recv(1024       )
															if not data:
																				break
															out_file.write(__a       )

					print('''Successfully received the file'''       )
					sock.close()
					print('''Connection closed'''       )


if __name__ == "__main__":
		main()