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]: ['315', '9975', '3013', 's', '6131', 'e', 'e', 'u', 'a', '1729', 'g', 't', 'y', 'f', '7523', 'e', 'g', '489', 'm', 'p', 'f', 'e', '2077', 'e', 'g', 'c', 'l', '6389', 'k', 'b']
[A]: a, b, c, e, f, g, k, l, m, p, s, t, u, y


[Q]: ['6411', 'x', 'i', '267', 'z', 'e', '5483', '8033', '3697', 'z', '4167', 'e', 'f', '7229', 'i', 't', '2197', 'g']
[A]: e, f, g, i, t, x, z


[Q]: ['2097', '7777', '311', 'z', '1707', 'u', '4039', '6843', '3453', 'j', 'i', 'a', 'e', '6481', '6539', 'q']
[A]:
a, e, i, j, q, u, z