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: ['t', 't', 'p', '3245', 'x', 'g', 'i', 'u', '2599', '8613', 't', 'v', 'p', '5635', 'y', '9567', '5193', '8617', 'q', 'f']

A: f, g, i, p, q, t, u, v, x, y
****
Q: ['7591', '1403']

A: -1
****
Q: ['6483', '963', 'f', 'b', '8321', '2439', 'k', 'h', 'x', 'p', '1649', '3495', 'z', '4051', 't', 'a', 'k', 'w', '3743', '5389', '8619', '1707', 'd', 'j', '3749', '7253', '8767', '4821', '2911', 'l', 'n', 'f', '4501', 'j', '1415', 'h', 'p', '7349', 'l', '8531', 'f', 'g', 'e', 'i', 'x']

A:
a, b, d, e, f, g, h, i, j, k, l, n, p, t, w, x, z
****