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]: ['f', 'p', 'n', '839', '9229', 'r', '7661', 'c', '4383', 'u', 'k', '5321', '3181', '1785', 'w', 'k', '8721', '7855', '4093', '6495', 'q', '2467', 'g']
[A]: c, f, g, k, n, p, q, r, u, w


[Q]: ['r', 't', '3539', 'z', 't', '6055', 'r', '5787', '8469', 'p', 'h', '9729', 'z', '1637', '5873', 'c', '3597', '4411', 's', 'k', 'q', '6471', '5375', 'e', 'v', 'i', '7425', 'h', '9079', 'd', '1585', '6011', 'x', '5669', '5219', '4951', '4765', '8285', '2811', 'c', '1805', '6463']
[A]: c, d, e, h, i, k, p, q, r, s, t, v, x, z


[Q]: ['8743', 'k', 'q', '991', '2231', '7647', '9369', '6913', '6965', 'n', '6645', '6243', 'e', 'h', 'y', 'u', '7007', '6027', '1645', 'e', '5365', 't', '7857', '7151', 'x', 'c', 'k', '4255', 'l', 'e', '3587', 'o', '4871', '9951']
[A]:
c, e, h, k, l, n, o, q, t, u, x, y