class Bike(object):
    def __init__(self,price,max_speed,miles=0)
        self.price=price
        self.max_speed=max_speed 
        self.miles=miles
    def displayinfo(self):
        print(price,max_speed,miles)
        return self
    def ride(self)
        print('Riding',miles + 10)
        return self
    def reverse(self)
        print('Reversing',miles - 5)
    