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.
--------
Question: ['q', 'o', '1205', '4429', '6301', 'e', '2857', '5075', '5121', 'p', 'b', '5801', 'a', 'm', 'j', 'p', '1279', '7011', 'x', '2557', 'k', 'v', 'b', 'u', 'w', 'n', '1689', 'o', '1583', 'w', '6403', 'p', '6397', 'e', '823', '5699', 'd', '3399', 'd', 'b']

Answer: a, b, d, e, j, k, m, n, o, p, q, u, v, w, x


Question: ['459', '1729', 'b', 'c', '9619', '4461', '4347', '6733', 'i', '3631', 's', 'j', 'i', 'r', '5293', 'q', '7397', '4309', 'c', 'n', 'k', '197', 'q', '8139']

Answer: b, c, i, j, k, n, q, r, s


Question: ['3617', 'k', 'j', '7057', '3275', 'y', '8073', 'i', 'w', '7553', '2377', 'k', '5025', 'd', 'x', 'h', 'y', 'z', '9281', '6719', 'x', 'j', 'v', '9833', 'n', '4217', '9883', 'a', '2955', 'f']

Answer:
a, d, f, h, i, j, k, n, v, w, x, y, z