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: ['v', '3765', '4065', 'a', '4201', 'f', 'x', '9275', 'q', '9303']

A: a, f, q, v, x
****
Q: ['1429', '7273']

A: -1
****
Q: ['8459', '1005', 'k', 'g', '8153', '8615', 'm', '825', 'g', '275', 'c', 'i', 'f', '5615', 'n', 'l', '6243', '1037', '8801', '2337', 'm', 'r', 'w', 'i', 'h', 'h', 'x', '6941']

A:
c, f, g, h, i, k, l, m, n, r, w, x
****