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.

Ex Input:
['6181', 'w', '4663', '5507', 'a', '6607', '869', '2669', 'r', '3629', 'r', 'l', '6599', '8885', 's', '4315', 'z', 'l', 'r', '1225', '8371', '1545', '7169', '1175', 'k', 'p', 'y', '7263', '5537', '8649', '3317', 'q', 'r', 'u', 'd', '4647', 'u', 'y', 'h', '9753', 'q', '725']

Ex Output:
a, d, h, k, l, p, q, r, s, u, w, y, z


Ex Input:
['w', 'n', '729', '2491', 'n', 'x', '915', '1869', 'z', '8491', '9947', '561', '829', 'n', 't', 'i']

Ex Output:
i, n, t, w, x, z


Ex Input:
['a', 'l', '1781', 'h', 'd', '5893', 'g', '9033', '2227', '8335', '5287', '4663', '7713', 'z', '9541', '5369', 'f', '9447', '9971', '3471', '5789', 'q', 'p', 'j', 'z', 'n', '233', '577', '9467', 'g', 'h', 'm', 'g', '2497', 'b', 'o', 'c', 'e', 'z', '3211', '6519']

Ex Output:

a, b, c, d, e, f, g, h, j, l, m, n, o, p, q, z