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: ['4927', 'h', 'x', '4719', 'j', 'f', '7797', 'l', 'i', 'q', 'x', 'i', 'k', '3215', 'k', '1625', 'g', 't', 'i', 'w', 'n', '6659', '8355', '831', 'h', '9723']

A: f, g, h, i, j, k, l, n, q, t, w, x
****
Q: ['3651', 'c', 'm', '7123', '2981', '9649', 'o', '2181', 'h', '8577', 'a', '5027', 'x', 'u', '1039', '347', '8219', 'c', '1063', '8885', 'f', 'd', '3067', '2509', 'i', 's', '5509', '2003', 'h', '8869', 'x', 'd', '5141', 'h', 'i', 'b', 'o']

A: a, b, c, d, f, h, i, m, o, s, u, x
****
Q: ['w', 'r', '1911', '6347', 'o', 'z', 'h', '5781', 'x', 'y', 'a', 'm', 'd', '8239', '9851', '4379', 'o', '1423', '9399', '3571', '3697', '1975', 't', '953', 'x', '4987', '7889', 's', 'g', 'z', '5297', '9247', 'w', '7305', '5843', 'f', 'r', '9435', 't', 'o', '399', '6603']

A:
a, d, f, g, h, m, o, r, s, t, w, x, y, z
****