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: ['57', 'j', 'n', '877', 'u', 'w', 'j', 'f', '8977', 'h', '469', '9417']

A: f, h, j, n, u, w
****
Q: ['3395', '7471', 'n', '9537', '1255', '1997', '3085', '4863', '9797', '4275', 'k', 'f', '8973', '3939', 'p', 'q', '4977', '6231', '8745']

A: f, k, n, p, q
****
Q: ['o', '17', 'c', '1169', 'v', '4051', '5995', 'a', '1353', '7513', '3911', '3347', '3903', 'q', 'b', '481', 'd', 'd', '805', 'y', '1877', '6653', 'e', '8405', '3747', 'g', 'w', 'e', 'j', '5147', 'a', '8869']

A:
a, b, c, d, e, g, j, o, q, v, w, y
****