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]: ['g', '7517', '3173', 'd', '2143', 'n', '8507', 'l', '8369', '225', 'e', 'l', '9511', 'p', '1317', '5651', 'p', '1125', 't', '739', '6453', 'l', 'g', '8555', '8075', 'x', 's', 'd']
[EX A]: d, e, g, l, n, p, s, t, x

[EX Q]: ['6249', '1235']
[EX A]: -1

[EX Q]: ['3487', '5383', 'd', 'q', '4561', '2649', '8683', '8347', '1137', '6493', 'k', '5523', '9005', 'j', 'v', '5139', 'o', '171', '6619', '5297', 'm', 's', '3219']
[EX A]:
d, j, k, m, o, q, s, v