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]: ['s', 'w', 'c', '4137', 't', '2437', '349', 'h', '4539', 't', 'b', 'y', 'q', 't', '9087', 'c', '9489', '6285', '6247', '8353', 'n', 't', '8661', 'p', 'z', 'p', '773', 'w', 'q', '8081', 'r', 'u', 'z', 'k', 'a', 'b', '7513', '5549', '5325', '1101', 's', '6507', '3317']
[EX A]: a, b, c, h, k, n, p, q, r, s, t, u, w, y, z

[EX Q]: ['i', 'x', 'n', 'w', '8915', 'd', 'd', 'd', '6025', '7861']
[EX A]: d, i, n, w, x

[EX Q]: ['7097', '7557', '9381', '4989', 'c', 'g', '2413', '3619', '5657', '8065', 't', '529', 'e', 'l', 'p', 'd', 'e', 'q', '6833', '9057']
[EX A]:
c, d, e, g, l, p, q, t