You will be given a definition of a task first, then some input of the task.
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.

hOHODOSHIdGW, HEHODOSXLFz
Output:
d, g, h, i, o, s, w