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]: ['1707', '381', '3957', '7853', '4987']
[EX A]: -1

[EX Q]: ['8887', '1199', 'r', '7209', 'k', '7567', '7239', 'k', '5123', 'w', '4523', 't', 'd', '5289', '5737', '485', 'w', 't', '7651', 'v', '7213', '7687', 'y', 'w', '7265', 'b', 'b', '3667', 'z', '9935', 'i', 'l', 'u', '6715', 'j', '9815', '8925', '7941', 'w', 'm', '3907', '621', '5523', '5849']
[EX A]: b, d, i, j, k, l, m, r, t, u, v, w, y, z

[EX Q]: ['l', 'c', '6973', '7951', '3355', 'y', 'f', '7981', 'a', '8717', 'j', '1555', 'c', '4337', 'w', '1301', 'r', '2311', '2409', 's', '9225', '3431', '259', 'v', '1443', 'z', 'l', '1205', '2697', 'h', '3633', 'o', '3617', 'j', '1381', 'r', '6683', 't', 'w']
[EX A]:
a, c, f, h, j, l, o, r, s, t, v, w, y, z