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]: ['n', '7489', 'n', 'n', '9787', '7829', 'n', '3481', 'v', 'l', '8927', 'c', 'm', 'd']
[EX A]: c, d, l, m, n, v

[EX Q]: ['9783', '3185', '8225', 'u', '1123', 'd', '3453', 'i', '7713', '8457', '8609', 'h', '2767', 'e', '7191', '2929', '1089', '393', 'e', 'd', '11', '9329', '683', '1271']
[EX A]: d, e, h, i, u

[EX Q]: ['8359', 'k', 'e', '1613', '127', 'r', '9347', 'x', '8489', 'q', 'w', '9435', 'k', 'a', 'k', 'b', '5539', '8941', 'k', '2331', 'c', 'h', '7257', '6949', '9857', '9711', 'h', '1323', '4051', '7879', 'l', 'r', '6729', '1165', 'b', 'r', 'u', 'w', 'q']
[EX A]:
a, b, c, e, h, k, l, q, r, u, w, x