PROGRAMMING:Department store promotion
###Task description
A department store uses the method of shopping discount to promote goods. According to the input amount of shopping, the company calculates and outputs the actual payment amount of customers. The discount rate of customers' one-time shopping is: (1) no discount for less than 500 yuan（ 2) For those over $500 and less than $1000, a 15% discount will be given（ 3) 10% discount for those over $1000 and less than $2000（ 4) 25% discount for those over 2000 yuan and less than 3000 yuan（ 5) 20% discount for 3000 yuan and above. Program input purchase amount and paid amount, output discount rate and actual payable amount and change amount.
###Input format:
There are two real numbers separated by spaces in a row. The first is the total amount of consumption and the second is the amount actually paid.
###Output format:
The first line outputs discount information, the second line outputs discounted amount, and the third line outputs change amount.
###Input example:
```in
5013 4050
```
###Output example:
```out
80%
four thousand and ten point four zero
thirty-nine point six zero
```
answer：If there is no answer, please comment
A department store uses the method of shopping discount to promote goods. According to the input amount of shopping, the company calculates and outputs the actual payment amount of customers. The discount rate of customers' one-time shopping is: (1) no discount for less than 500 yuan（ 2) For those over $500 and less than $1000, a 15% discount will be given（ 3) 10% discount for those over $1000 and less than $2000（ 4) 25% discount for those over 2000 yuan and less than 3000 yuan（ 5) 20% discount for 3000 yuan and above. Program input purchase amount and paid amount, output discount rate and actual payable amount and change amount.
###Input format:
There are two real numbers separated by spaces in a row. The first is the total amount of consumption and the second is the amount actually paid.
###Output format:
The first line outputs discount information, the second line outputs discounted amount, and the third line outputs change amount.
###Input example:
```in
5013 4050
```
###Output example:
```out
80%
four thousand and ten point four zero
thirty-nine point six zero
```
answer：If there is no answer, please comment