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

[EX Q]: ['4213', '3595', '7937', 'y', '5723', 'v', 'b', '7007']
[EX A]: b, v, y

[EX Q]: ['3861', 'm', '6703', 'e', '7691', 'l', '647', 'r', 'd', '8999', 'y', 'z', '1451', 'q', 'm', '6843', 'w']
[EX A]:
d, e, l, m, q, r, w, y, z