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: ['8829', 'm', '5369', 'q', '5737', '7799', '5705', 'p', 'w', '1983', '4849', 'h', '6771', 'p', 'y', '1071', 'u', '6401', '7723', 'p']

A: h, m, p, q, u, w, y
****
Q: ['k', 'z', '303', 'a', 'f', 'q', 'i', '1475', '3453', 'd', 'w', '4037', 'z', 'h', 'k', '3547', '1561']

A: a, d, f, h, i, k, q, w, z
****
Q: ['m', 'g', 'e', '1135', '651', 'd', '1505', '279', '8007', 'o', 'a', 'r', '8249', '6237', 'v', '1441', 'v', 'h', '1115', 'u', 'l', 's', '6341', '8361', '8759', 'v', '3781', '1345', 'x', '8193', 'm', 'l', 'e', 's', '7469', 'u']

A:
a, d, e, g, h, l, m, o, r, s, u, v, x
****