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.

Example Input: ['a', '533', '67', 'z', 'z', '9283', 'o', 'a', '7045', '1521', 'm', 'h', 'q', '4173', '7497', '319', '5721', '6097', 'i', '9829', '1801', '7347', 'r', 'z', '239', '4279', 'e', 'k', 'r', 'v', '6653', '599', '8597', 'd', 'r']
Example Output: a, d, e, h, i, k, m, o, q, r, v, z

Example Input: ['5011', 'l', '925', 'e', 'b', '3077', 'm', '4541', '781']
Example Output: b, e, l, m

Example Input: ['k', 'z', '877', 'l', '4739', '6417', '8125', 'd', '8007', 'z', 'l', '1627', '55', '7863', '1759', '6291', '2853', 'u', 'r', '3899', '3377', '8453', 'r']
Example Output:
d, k, l, r, u, z