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]: ['p', '9641', '8515', '1207', 'd', 'j', '6617', '5529', 'g', 'a', 'o', 'f', 'y', '4993', '4643', '6087', 'n', '3177', 'y', '9471', '1229', '8211', '7079']
[EX A]: a, d, f, g, j, n, o, p, y

[EX Q]: ['395', '8309', 'v', 'r', 'x', 'j', 'l', 'b', 'c', 'c', '3123', 't', 'a']
[EX A]: a, b, c, j, l, r, t, v, x

[EX Q]: ['y', 'w', 'p', '1445', '643', '7947', '7325']
[EX A]:
p, w, y