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]: ['w', '491', 'x', 'u', 'z', 'q', '5411', '7629', '8261', '8629', '1441', '5139', 's', 'm', '6463', 'u', 'z']
[EX A]: m, q, s, u, w, x, z

[EX Q]: ['9023', '9379', 'n', '9745', 'o', '2677', '4645', '9833', 'x', 'o', '3993', 'r', 'q', '9335', 'k', 'd', 'c', '7753']
[EX A]:
c, d, k, n, o, q, r, x