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]: ['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]: ['3395', '7471', 'n', '9537', '1255', '1997', '3085', '4863', '9797', '4275', 'k', 'f', '8973', '3939', 'p', 'q', '4977', '6231', '8745']
[EX A]: f, k, n, p, q

[EX Q]: ['o', '1207', '7193', '3495', '425', '281', '911', '1915', 'x', 'y', '4989', '8901', 'f', 'w', 'k', '6983', 'b', '3053', '793', '7587', '7911', '4769', 's', 'h', '4451', 's', 'w', 's', '973', '6969', '6027', '8115', '6721']
[EX A]:
b, f, h, k, o, s, w, x, y