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.

['2409', 'q', 'w', 'e', 'x', '4737', 'w']
e, q, w, x

['w', '9437', 's', '9819', 'q', 'q', '4443', 'p', '377', '6777', 's', 'x', 'a', 'o', '9205', '9289', '7103', 'k', 'l', '9453', '9043', 'k', 'r', 'g']
a, g, k, l, o, p, q, r, s, w, x

['3385', '61', 'o', 'h', 'h', '9851', '4043', 'x', 'e', '4157', 'o', '3499']

e, h, o, x