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]: ['1983', '1835', '6543', '6399', '4177', '9385', '7127', 'p', 'l', 'u', 'g', 't', '3423', 'g', 'b', 'l', '3133', '2429']
[A]: b, g, l, p, t, u


[Q]: ['8975', '7199']
[A]: -1


[Q]: ['t', 'q', 'g', 'z', '2953', '4353', '625', 'n', '7667', '6875', 'z', 'e', '159', 'p', '483', 'e', 'v', 'p', '6741', '339', 'q', '749', 'f', '6955', '4523', '527', '7949', 'd', 'u', 'w', 'i']
[A]:
d, e, f, g, i, n, p, q, t, u, v, w, z