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.

Example input: JkbloNUq, nYblowj
Example output: b, j, k, l, n, o, q, u
Example explanation: Here, 'JkbloNUq' is the longer string among the two input strings. Lowercasing it and finding all unique alphabets gives 'b, j, k, l, n, o, q, u'.
Q: CRmmGXKse, MzmmGXKYtoYb
A:
b, g, k, m, o, t, x, y, z