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]: ['i', '4447', 'g', 'o', 'j', 'p', 'l', 'q', 'o', '8777', 'r', 'v', '961', '6083']
[EX A]: g, i, j, l, o, p, q, r, v

[EX Q]: ['l', '6313', '3199', 'w', '249', '8747', '7391', '3871', '173', 'x', 'o', '8647', '4413', '3645', '6123', '701', 'q', '2147', '4289', '7333', '533']
[EX A]: l, o, q, w, x

[EX Q]: ['k', 'y', 'w', '2483', 'b', 'n', 'r', 'l', '577', 'f', '519', '2069', 't', 'n', '7479', 'e', 'v', '8627', 'g', 's', '3929', '7317', '7021', 'n', 'c', '4347', 'l', 'b', '9541', '569']
[EX A]:
b, c, e, f, g, k, l, n, r, s, t, v, w, y