In this task, you are given two strings A,B. Find the longer of the two lists, convert it to lowercase, and return all the unique alphabets used in it. The two input strings are never equal.
Q: GqKxSBN, LdKxStTS
A: 
user
the longer string is ldkxstts. converting it to lowercase and returning the unique alphabets, we get "ldkxst".
assistant
The longer string is LdKxStTS. Converting it to lowercase and returning the unique alphabets, we get "ldkxst".
assistant