class Hero:
    def __init__(self, username, level)
    self.username = username
    self.level = level
    
    def __str__(self):
        return f"{self.username} of type {self.__class__.__name__} has level {self.level}"
    
class Elf(Hero):
    pass

class MuseElf(Elf):
    pass

class Wizard(Hero):
    pass

class DarkWizard(Wizard):
    pass

class SoulMaster(DarkWizard):
    pass

class Knight(Hero):
    pass

class DarkKnight(Knight):
    pass

class BladeKnight(DarkKnight):
    pass