class dongwu():
    def waik(self):
        print('会走路')
    def food(self):
        print('吃食物')
class dog():
    def waik(self):
        print('会走路')
    def food(self):
        print('吃食物')
class fish():
    def waik(self):
        print('不会走路')
    def swim(self):
        print('会游泳')


