class Error:
	def __init__(self, value):
		self.value = value
	def __str__(self):
		return self.value
		
class AddressCardNotFound(Error): pass
class AddressFormatMalformed(Error): pass
class FileExists(Error): pass
class KeyNotSupported(Error): pass
class LetterNotWritten(Error): pass
class MalformedClause(Error): pass
class PathNotFound(Error): pass