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', 'c', 'o', 'e', 'n', 'q', 'w', '9475', 'w', '863', 'r', '2219', '3483', '5035', '8209', '7957', 'b', '3735', '1423', 'l', '3409', '7639', 'd']

A: b, c, d, e, l, n, o, q, r, w
****
Q: ['k', '8917', '3773', '6723', 'r', 'z', '3265', 'o', 'f', 'q', '9343', 'f', '1925', 'u', 'b', 'o', '5275', 'b', 'n', 'd', 'j', '4825']

A: b, d, f, j, k, n, o, q, r, u, z
****
Q: ['x', 'l', 'j', 'o', 'h', '8111', 'l', '7851', '333', '3077', '2601', 'p', 'b', 'o', 'h', '7887', '7591', '1609', '3757', 'o', 'b', '1379', 'a', 'u', '5023']

A:
a, b, h, j, l, o, p, u, x
****