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]: ['8235', 't', '1695', '9899', '3633', 't', '1823', 'r', 'x']
[A]: r, t, x


[Q]: ['8815', 'w', '8629', 'y', '3891']
[A]: w, y


[Q]: ['4645', '6519', '5047', '1695', 'g', '6743', '1097', 'v', '7749', 'o', 'r', 'y', 'x', '9141', 'j', 'r', '1801', 'x', '2225', 'i', 'q', 'd', 'x', '701', 'm', '4555', '1567', '2127', 'z', 'q', '4207', '9329', '4219', '1681', '9277', '2091']
[A]:
d, g, i, j, m, o, q, r, v, x, y, z