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.

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

A: j, m, n, o, q, s, y
****
Q: ['2799', '7519', '345', 'e', 'l', '9369', '4703', '4111']

A: e, l
****
Q: ['551', '3085', '183', '2823', '977', '4687', '671', '5655', 'k', '1777', '9241', '4013', '751', 'd', 'd', '7161', '9355', '2697']

A:
d, k
****