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: ['2697', 's', '8733', 'n', '5871', 'f']

A: f, n, s
****
Q: ['6463', '871', '5781', '283', '9653', 'f', '9661', '3365', '2889', '5499']

A: f
****
Q: ['e', 'n', 'e', '5229', 'j', '6173', '91', '9201', 'x', 'o', 'h', '8721', 'c', 'y', '9157', 'm', '7819', 'w', '6565', '4229']

A:
c, e, h, j, m, n, o, w, x, y
****