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]: ['895', '2049', '8839', '1773', 'v', '467']
[EX A]: v

[EX Q]: ['747', '5385', '5313', 'p', '9581', 'r', '1339', '3919', 'e', 'e', '8057', '7739', 'i', 'e', '3311', '963', 'g', 'h', '7349', 'y', '1493', 'e', '3055']
[EX A]: e, g, h, i, p, r, y

[EX Q]: ['c', '9505', 'a', '8731', 'f', 'p', 'b', 'a', 'v', '9393', '5807', 's', 'n', 'a', '6719', 'x', '1365', 't', '4877', '4021', 'k']
[EX A]:
a, b, c, f, k, n, p, s, t, v, x