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: ['2409', 'q', 'w', 'e', 'x', '4737', 'w']

A: e, q, w, x
****
Q: ['r', 'y', 'c', '3211', '9245', '8459', '8521', '5781', 'w', 's', 'd', '5299', 'a', 'y', 'g', 'm', '6435', '8605', 'e', 'h', '6871', 's', '387', 'l', '5829', 'e', 'd', '9545', '2945', 'k', 'v', 't', '8449', '2199', 'm', '2599', '1489', '6623', 'x', 'l']

A: a, c, d, e, g, h, k, l, m, r, s, t, v, w, x, y
****
Q: ['d', 't', '3253', '9881', '2581', 'n', 'x', 'r', '5485', '9555', 'r', '2569', '5203', '7355', '3863', 'i', '1285', 'c', 'w', 'p', 'x', 'x', '7047', '6441', '9653', '3099', 'u', 'l', '1715', '139', '4801', '9045', '5013', '6793', 'q', '79', '9123', 'c', 'y', 'a', '779']

A:
a, c, d, i, l, n, p, q, r, t, u, w, x, y
****