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]: ['2527', '9123', '8717']
[A]: -1


[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]: ['q', '9119', 'r', 'a', 'x', 'p', 'z', 'g', 'w', 'h', '3711', 'z', 'h', '8085', 'r', '9767', 'g', '7173', '627', 'x', '1481', '635', 's', '7531', 'l', '8489', '8021', '1423', '2033', '6905', '7835', 'r', '8419', 'x', '3411', '2067', '5641', '9963']
[A]:
a, g, h, l, p, q, r, s, w, x, z