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: ['o', 'v', 'w', '7939', '571', '395', '3707', 'm', 'd', 'u', 'o', 'r', '4211', '9645', '8731', '2441', 'y', '8147', '8809', 'e', 'b', '6835', 'i', '2083', 't', '3481', 'f', 'f', '5559', '3601', 'e', '5637', '5185', 't', '6777', '3419', '8637', 'p', 's', 'o', 'x']

A: b, d, e, f, i, m, o, p, r, s, t, u, v, w, x, y
****
Q: ['9923', 'x', '1901', 'v', '1459', '7503', '3829', '4929', 'k', 'c', '3329', '8793', 'n', 'a', '7249', 'b', 'l', 'l', 'm', 'p', 'b', 'a']

A: a, b, c, k, l, m, n, p, v, x
****
Q: ['w', '4975', '6041', '1243', '9417', 'v', 'f', 'q', 'q', '3315', '9641', 'p', 'p', 'i', '6157', 'l', 'p', 'g', '1071', '3397', 'o', '6057', 'd', '7915', '8209', '7967']

A:
d, f, g, i, l, o, p, q, v, w
****