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]: ['4641', '2881', 'c', '4827']
[EX A]: c

[EX Q]: ['9273', '5219', 'e', '9413', 'v', 'h', '5657', '797', '2303', '2119', '4791', '2757', '4983', 'h', '9681', '4503', '6657', 't', 'i', 'g', '9375', '9901', 'm', 'y', '6461', 'h', '6663', '9493', '5897', '8829', 'd', 'x', '901', '833', 'u']
[EX A]: d, e, g, h, i, m, t, u, v, x, y

[EX Q]: ['6635', 'z', '3543', '8407', '9263', '1665', '317', 'm', '8729', 'l', '1409', '6299', 'x', 'n', '1679', '6459', 'y', 'x', '6321', 'o', 'n', 'i', '5773']
[EX A]:
i, l, m, n, o, x, y, z