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: ['8489', 'h']

A: h
****
Q: ['1121', 'j', '1433', 'g', 'l', '1479', '1699', 'j', 'a', '8507', 'd', 'a', '5229', 'k', 'x', '4549', 'e', 'p', '1367', 'u', 'd', '785', '215', 'e', 'f', 'a', '101', '7575', '7965', 'p', 'i', '5637', '1005', 'i', 'y', '181', 'r']

A: a, d, e, f, g, i, j, k, l, p, r, u, x, y
****
Q: ['6129', '6809', 'u', 'x', '5247', '2697', '7095', '7813', '8209', '9491', 'w', '1039', '8439', '1491', 'u', 'y', '3933', '8531', '2675', 'h', '417', '5819', 'k']

A:
h, k, u, w, x, y
****
