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]: ['g', '7517', '3173', 'd', '2143', 'n', '8507', 'l', '8369', '225', 'e', 'l', '9511', 'p', '1317', '5651', 'p', '1125', 't', '739', '6453', 'l', 'g', '8555', '8075', 'x', 's', 'd']
[A]: d, e, g, l, n, p, s, t, x


[Q]: ['k', 'r', 'f', '4369', 'z', 'z', 'l', '143', 'r', '707', '9167', 'g', '1749', 'i']
[A]: f, g, i, k, l, r, z


[Q]: ['f', '9459', 'm', 'q', '4593', '3325', 'y', 'c', 'r', '3597', '8657', 'y', 'e', '7677', '543', '7959', '6257', 'j', '883', 'k', 'o', '2399', '8903', 'g', 'f', 'h', '7835', 'd', 'q', 'g', '7563', '4681', 'f', '6763', 'f', '2021', '8051', 'w', 'f', '39', 'a', '129', '1557']
[A]:
a, c, d, e, f, g, h, j, k, m, o, q, r, w, y