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]: ['815', '6967', '6553', 'r', 'y', '3641', 'q', 'b', '6131', '4289', 'w', '6093', '6055', 'i', 'b', 'y', '5107', 'v', 'g', '9709', 'x', 'i']
[A]: b, g, i, q, r, v, w, x, y


[Q]: ['c', '8389', 'j', '6113', '5843', 'f']
[A]: c, f, j


[Q]: ['5077', '4437', '4189', '8819', 'h', '7855', '6873', '7815', 'i', '8575', 'u', '29', '9417', 'k', '9925', 'n', '7507', 'r', '2939', '1145', '6309', '5799', '8663', 'j', '4077', 'd', 'v', 'o', '1557', '2559', '9329', 'h', '3207']
[A]:
d, h, i, j, k, n, o, r, u, v