



def  UpperCAmelCase__    (    lowercase__ = 1_000   ) ->      int:
						return sum(2 * a * ((a - 1) // 2) for a in range(3						,       n + 1   )   )


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










def  UpperCAmelCase__    (    lowercase__						,       lowercase__   ) ->      int:
						if len(lowercase__   ) != len(lowercase__   ):
												raise ValueError("""String lengths must match!"""   )

						__lowercase					=				0

						for chara, chara in zip(lowercase__						,       lowercase__   ):
												if chara != chara:
																		count += 1

						return count


if __name__ == "__main__":
			import doctest

			doctest.testmod()





