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]: ['7911', '7175', 'y', '9173', 'y', '2529', '831', 'k', '7197', 'j', '2343', 'i', 'b', '6799', '5987', '7277', 'n', 'x', 'h', '7209', 'l', 'd', 'm', 'e', '2277', '8909', 'x', '5361']
[EX A]: b, d, e, h, i, j, k, l, m, n, x, y

[EX Q]: ['a', 'a', 'b']
[EX A]: a, b

[EX Q]: ['b', 'u', '261', 'z', 'w', 's', '8183', 'p', '7855', 'h', '9275', '5687', 't', 'k', '183', 't', '4175', '5641', '6471', '7941', '1993', '157', 'e', '9455', 'j', 'c']
[EX A]:
b, c, e, h, j, k, p, s, t, u, w, z