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: ['a', 'a', 'b']

A: a, b
****
Q: ['7839', '849', '5651', '4275', 'e', '5453', 'h', '2099', '485', 'i', 'm', 'n', '6563', '5675', '4001', 'h', 'm', 'z', '3467', '4237', '5035', '5609', '8475', '5171', 'v', '3883', '8461', '8611', '4853', 'd']

A: d, e, h, i, m, n, v, z
****
Q: ['v', 'q', '4857', 'b', '6643', '6551', 'e', 'f', '7373', 'w', '2881', 'c', '6189', '3923', 'm', 'w', '9071', '4899', '5987', '5491', 'j', '5109', 'o', '8565', 'n', 'a', 'i', '8363', '8411', '8693', 'q', '4261', '6861', 'l', 'k', 'x', '7899', '4909', 'l', 'x', 'd']

A:
a, b, c, d, e, f, i, j, k, l, m, n, o, q, v, w, x
****