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.

['f', 'p', 'n', '839', '9229', 'r', '7661', 'c', '4383', 'u', 'k', '5321', '3181', '1785', 'w', 'k', '8721', '7855', '4093', '6495', 'q', '2467', 'g']
c, f, g, k, n, p, q, r, u, w

['2165', 'f', '5081', 's']
f, s

['6351', '4971', 'h', '2703', 'd', '3829', '1511', 'i', '7039', '5755', '6451', 'h', '1279', '8907', '133', 'v', 'b', '2515', '3221', '927', '3591', 'j', 'j', '2683', 'q', '5601', 'i', 'q', '5383', '7725']

b, d, h, i, j, q, v