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]: ['8489', 'h']
[EX A]: h

[EX Q]: ['4857', 'z', '313', '7813', '9935', 'o', 'w', 'i', 'x', 'o', 'e', 's', 'a', 'p', 'i', 'v', 'x', '6743', 'p', '435', 'u', 'a', 'h', '607', '2491', '6159', 'u', '7761', '6197', '3449', '3459', 'e', 'g', '8731', '335', '2883', '3941', 'n', '1881', 'y', 'j', '8189', 'k', '7593', '2747']
[EX A]: a, e, g, h, i, j, k, n, o, p, s, u, v, w, x, y, z

[EX Q]: ['n', '891', '8181', 'f', 'b', 'b', 't', '9715', 'r', 'u', 't', 'n', 'e', '4671', '5527', 'r']
[EX A]:
b, e, f, n, r, t, u