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]: ['z', '3219', '6399', '2357', '7597', '357', 'k', 'k', 'u', 'd', '6115', 'w', '2921', '8809']
[EX A]: d, k, u, w, z

[EX Q]: ['h', 'l', 'i', '1507', 'h', '409', '6777', 'u', '5563', '6113', '6513', '9949', '461', 'z', 'm', '2519', 'r', '4699', 'n', 'x', '4645']
[EX A]: h, i, l, m, n, r, u, x, z

[EX Q]: ['3095', 'y', 'w', '5993', 'w', '9413', '625', 'p', 's', '1989', '7787', 't', '883', '5465', '9293', '7895', 'b', '3443', '4179']
[EX A]:
b, p, s, t, w, y