



def __lowerCAmelCase	(       SCREAMING_SNAKE_CASE_					):





			if not all(x.isalpha() for x in string					):
						raise ValueError("String must only contain alphabetic characters."					)

			lowercase__   					=			sorted(string.lower()					)
			return len(SCREAMING_SNAKE_CASE__					) == len(set(SCREAMING_SNAKE_CASE__					)					)


if __name__ == "__main__":
							lowercase_						=       input("""Enter a string """).strip()

							lowercase_						=       is_isogram(input_str)
							print(F'{input_str} is {"an" if isogram else "not an"} isogram.')









from __future__ import annotations



def __lowerCAmelCase	(       SCREAMING_SNAKE_CASE_					):
			return len(set(SCREAMING_SNAKE_CASE_					)					) == len(SCREAMING_SNAKE_CASE_					)


if __name__ == "__main__":
							import doctest

							doctest.testmod()




