Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE Discount_Coupons (coupon_amount VARCHAR, coupon_id VARCHAR)
TABLE: CREATE TABLE customers (coupon_id VARCHAR, good_or_bad_customer VARCHAR)

### Question ###
What are the coupon amount of the coupons owned by both good and bad customers?

### Accurate SQL ###

SELECT T1.coupon_amount FROM Discount_Coupons AS T1 JOIN customers AS T2 ON T1.coupon_id = T2.coupon_id WHERE T2.good_or_bad_customer = 'good' INTERSECT SELECT T1.coupon_amount FROM Discount_Coupons AS T1 JOIN customers AS T2 ON T1.coupon_id = T2.coupon_id WHERE T2.good_or_bad_customer = 'bad'