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]: ['w', '1367', '5389', '9515']
[A]: w


[Q]: ['3995', 'n', 'z', '8389', '7857', '3005', 'i', 'e', '1117', 'z', '8251', 'r', 't']
[A]: e, i, n, r, t, z


[Q]: ['u', '4939', '5635', '7613', 'z', '6481', '8467', 'h', 't', 'p', '375', 'v', 'h', '885', '3831', '7577', '4557', 'f', 'z', '1479', '8137', 'e', 'p', 'q', 'i', '8507', 'o', 'h', '1601', 'o', 'l', '3413', 'y']
[A]:
e, f, h, i, l, o, p, q, t, u, v, y, z