In this task, you are given an input list A comprising of numbers and alphabets. You need to extract and sort the unique alphabets in the list. The alphabets in the input list will only be in lowercase. Return -1 if there is no alphabet in the input list.

[Q]: ['8859', '575', 'l', 'e', '6575', '1303', '8643', '1395', '3171']
[A]: e, l


[Q]: ['q', 'c', 'o', 'e', 'n', 'q', 'w', '9475', 'w', '863', 'r', '2219', '3483', '5035', '8209', '7957', 'b', '3735', '1423', 'l', '3409', '7639', 'd']
[A]: b, c, d, e, l, n, o, q, r, w


[Q]: ['x', 'f', '6351', '6297', '1341', 'n', '8403', 'q', '1449', 'q']
[A]:
f, n, q, x