设计一个表示用户的User类，类中的变量有用户名、口令和记录用户个数的变量，定义类的构造方法、获取和设置用户名、口令的方法和返回帐户信息(第几个帐户，帐户名，密码)的方法

class User:
    count = 0

    def __init__(self, username, password):
        self.__username = username
        self.__password = password
        User.count += 1

    def get_username(self):
        return self.__username

    def set_username(self, new_username):
        self.__username = new_username

    def get_password(self):
        return self.__password

    def set_password(self, new_password):
        self.__password = new_password

    def get_account_info(self):
        return f"Account {User.count}: Username - {self.__username}, Password - {self.__password}"

使用示例：

user1 = User("Alice", "123456")
print(user1.get_account_info())  # Account 1: Username - Alice, Password - 123456

user2 = User("Bob", "abcdef")
print(user2.get_account_info())  # Account 2: Username - Bob, Password - abcdef

user1.set_username("Alicia")
user1.set_password("654321")
print(user1.get_account_info())  # Account 1: Username - Alicia, Password - 654321