


"""simple docstring"""
def 		lowercase							(     _snake_case						:      str     )     ->bool:
	"""simple docstring"""





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

	__snake_case	:						Union[str, Any]						=				sorted(string.lower()     )
	return len(_snake_case     ) == len(set(_snake_case     )     )


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

			SCREAMING_SNAKE_CASE :    Optional[int]									=				is_isogram(input_str)
			print(F'{input_str} is {"an" if isogram else "not an"} isogram.')







import os
from distutils.util import strtobool
def  lowerCAmelCase__			(  SCREAMING_SNAKE_CASE_       ,							SCREAMING_SNAKE_CASE_     )				->		Optional[Any]:
			for e in env_keys:
						lowerCAmelCase__      :      Union[str, Any]         =		int(os.environ.get(SCREAMING_SNAKE_CASE_       ,							-1     )     )
						if val >= 0:
									return val
			return default
def  lowerCAmelCase__			(  SCREAMING_SNAKE_CASE_       ,							SCREAMING_SNAKE_CASE_=False     )				->		List[str]:
			lowerCAmelCase__      :      Optional[int]         =		os.environ.get(SCREAMING_SNAKE_CASE_       ,							str(SCREAMING_SNAKE_CASE_     )     )
			return strtobool(SCREAMING_SNAKE_CASE_     ) == 1  # As its name indicates `strtobool` actually returns an int...







def  lowerCAmelCase__			(  SCREAMING_SNAKE_CASE_       ,							SCREAMING_SNAKE_CASE_="no"     )				->		List[str]:
			lowerCAmelCase__      :      Optional[int]         =		os.environ.get(SCREAMING_SNAKE_CASE_       ,							str(SCREAMING_SNAKE_CASE_     )     )
			return value