Roughly calculate how much you will charge if you don't have 5000 yuan a month. The first is the late payment fee, which is 5% of the unpaid part of the minimum repayment amount. The minimum repayment amount is about 10% of the total amount, so it is 500*5%=25 yuan. This is only the late payment for the first month. After the second and third months, there will be more and more late fees. Because there is no repayment in the first month, the minimum repayment amount will be higher and higher. Then deduct interest, charge interest at the rate of five ten thousandths per day, and compound interest monthly. 5000*0.05%=2.5 yuan/day, that is to say, the interest for the first month is 2.50 yuan/day, calculated every day. For example, 30 days is 2.50*30=75 yuan's interest. In the second month, the interest will be paid together with the principal, and then the interest will be paid, (5000+75)*0.05%=2.54 yuan/day. This one-month interest plus late payment fee is 100, and there will be more in the next few months. It's hard to figure out how much it will be in five years, but that's how the algorithm comes about.