Table schema:
CREATE TABLE customers (customer_id VARCHAR); CREATE TABLE products (product_name VARCHAR, product_id VARCHAR); CREATE TABLE complaints (product_id VARCHAR)

Question: Which products has been complained by the customer who has filed least amount of complaints?
SQL: SELECT DISTINCT t1.product_name FROM products AS t1 JOIN complaints AS t2 ON t1.product_id = t2.product_id JOIN customers AS t3 GROUP BY t3.customer_id ORDER BY COUNT(*) LIMIT 1