On the first day of school, my mother said she would give me 800 yuan a month for living expenses, but I didn't have time to protest that the living expenses were too low. She added that you have to pay me back 1,000 yuan at the end of the month. I thought my mom was kidding me until she sent me a bill! If you didn't come back last week, 200 yuan would be deducted; on September 15, if you didn't say good morning, 5 yuan would be deducted; on September 20, if you didn't say good night, 5 yuan would be deducted; on September 21, if you didn't say good morning and good night, 10 yuan would be deducted; a total of 220 yuan will be deducted for living expenses in September.
