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]: ['n', 'q', '6461', 's', '8565', '2237', '2071', '8143', '2977', '5511', 'j', 'o', '5793', 'j', 'm', 'n', '8031', 'j', '535', '5001', 's', 'y', '1737']
[EX A]: j, m, n, o, q, s, y

[EX Q]: ['7839', '849', '5651', '4275', 'e', '5453', 'h', '2099', '485', 'i', 'm', 'n', '6563', '5675', '4001', 'h', 'm', 'z', '3467', '4237', '5035', '5609', '8475', '5171', 'v', '3883', '8461', '8611', '4853', 'd']
[EX A]: d, e, h, i, m, n, v, z

[EX Q]: ['4143', '8771']
[EX A]:
-1