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]: ['9425', 'l', 'c', 'n', '5925', '2543', '3935', 'c', '7533', 'j', 'q', '3775', '5897', '9435', '69', 'e']
[A]: c, e, j, l, n, q


[Q]: ['1801', 'q', '5101', '8863', '2309', 'p', '8789', '9529', '6135', '5523', 'f', '8889', '7639', 'k', '263', '5751', '5529', 'g', '1451', '4143', 'e', '6987']
[A]: e, f, g, k, p, q


[Q]: ['9821', 'n', 'p', 'b', '1437', '9277', 'i', 'y', 'p', 'c', 't', 'b', '9299', 'n', '6935', 'o', '6159', 'g', '5305', '4385', 'u', 'o', 'z', 'o', '9321', 'd', '7235', '3081', '3197', '3839', '541', 'y', 'h', 's', 'c', '4715', 'x', 'u', '9939', 'f']
[A]:
b, c, d, f, g, h, i, n, o, p, s, t, u, x, y, z