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.

[EX Q]: ['l', 'u', '3901', '341', '5801']
[EX A]: l, u

[EX Q]: ['a', '3281', '9123', '5443', 'w', 'w', 'p', '9275', 'v', 'm', '3549', 'l', 'y', 'l']
[EX A]: a, l, m, p, v, w, y

[EX Q]: ['4467', '8081', 'q', 'h', 'f', '4427', 'j', 'x', '6499', '6949', '159', 'a', 'k', '4209', 'm', 'h', '4409', 'p', 'x', 'l', '9481', 'z', 'f', '1139', 'q', '2707', 'z', '4755', 'g', '1671']
[EX A]:
a, f, g, h, j, k, l, m, p, q, x, z