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]: ['q', '6421', 'w', 'x', '669', 'h', '3853', '6609', 'p', '947', 'g', 'c', 'x', '2617', 'v', 'e', '4795', '5755', 'a', '2379', 'y', '5939', 'l', 'h', 'g', '3779', 'c', 'm', '3157', '4027', 'g', '2917', '9461', '7271', 't', 'i', '9807', '147']
[A]: a, c, e, g, h, i, l, m, p, q, t, v, w, x, y


[Q]: ['g', 'p', '2925', 'n', 'o', 'y', '6381', 'l', '4963', 'g', 'm', 'u', 't', '9389', '3787', '7713', '1251', '779', 'i', 'w', '9869', 'y', 'y', '3881', 'k', 't']
[A]: g, i, k, l, m, n, o, p, t, u, w, y


[Q]: ['4945', 'n', '6833', '8209', 'k', 'p', '3555', '5913', '3895', '2281', '2903', 'w', 'b', '7139', 'n', '1507', 's', 'i', 'n', '3251', '7635', 'g', 'o', 'd', '4157', '7155', '2863', '2799', '85']
[A]:
b, d, g, i, k, n, o, p, s, w