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.

[EX Q]: ['v', 'l', 'v', '7673', '8975', 'u', '2471', '4151', '3615', '1139', 'i', 'z', '8833', 'v', '341', 'l', 'n', 'l', 'd', '9207', '1861', '3901', 'a']
[EX A]: a, d, i, l, n, u, v, z

[EX Q]: ['653', '1969', '6235', '6283', 'd', 'e', '465', 'e']
[EX A]: d, e

[EX Q]: ['z', 'u', 'n', '9343', '9889', 'i', '9375', 'd', 'e', 'x', '793']
[EX A]:
d, e, i, n, u, x, z