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: ['j', '1733', 'p', '6741', '7933', '8943', '733', 'x', '1107', 'z', '1719', '7653', 'y', 'z', '6563', 'p', '4615', 'j', '4489', 'h', 'w', 'y', 'p', 'c', '7949', 'k', 'm', 'r', '9427', '7243', '9777', 'j', '323', '4095', 't']

A: c, h, j, k, m, p, r, t, w, x, y, z
****
Q: ['s', '185', '9925', 'q', '4839', 'r', 'v', '2121', 'y', 'i', '3669', '5197', '4211', 'm', '5385', 'i', 'q', '2983', 'i', 't', 'g', '7663', 'c', 'z', 'e', '7503', '5559', '6673', 'i', '6263']

A:
c, e, g, i, m, q, r, s, t, v, y, z
****