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]: ['1447', 'q', '9529', '2971', 's', '7351', '6753', '3493', 'v', 'c', 'x', '3097', '9145', 'b', 'e', 'b', '2967', '6933', 'e', 's', 'v', 'f', 'z', 'r']
[A]: b, c, e, f, q, r, s, v, x, z


[Q]: ['8821', '9833', 'l']
[A]: l


[Q]: ['5067', '1559', '3861', '1117', 'b', 't', '3375', '1035', 'z', 'b', '6783', 'd']
[A]:
b, d, t, z