Q: 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', '1857', '2261', '3671', 'q', '8383', '7689', 'z', 'q', '9371', '8687', 'i', '3167', '7857', 'h', 'w', '687', '3883', 'z', 'm', '7963', 'c', 'q', '4873', '4931', '4483', '5343', '1189', '6297', 'q', '2635', 's', '1957', 'b', 'b', 'r', 'm', '2989', '1247', '2449', 'x', 'u', '2579']
A:
b, c, h, i, m, q, r, s, u, w, x, z