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]: ['8311', 'w', 'f', '3431', '9863', '5817', '3969', '2705', 'x', 'm', 'k', 'z', 'z', '235', 'x', '417', 's', 'i', 'y', '8833', '8675', 's', 'm', '2149', '765', 'u', '1021', '7823', 'x', '7275', '3157', 'k']
[A]: f, i, k, m, s, u, w, x, y, z


[Q]: ['h', 'l', 'i', '1507', 'h', '409', '6777', 'u', '5563', '6113', '6513', '9949', '461', 'z', 'm', '2519', 'r', '4699', 'n', 'x', '4645']
[A]: h, i, l, m, n, r, u, x, z


[Q]: ['177', 'p', 'q', 'o', 'a', '2237', '1685', 'x', '6857', 'h', '9271', '9287', 'm', '5183', 'm', '3797', 'e', '6717', 'y', '971', 'a', 'o', '4157', 'p']
[A]:
a, e, h, m, o, p, q, x, y