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: ['2393', 'c', '4413', '5529', '1487', '2499', 'i', 's', 'i', '8575', 'm', 'z', '7179', '6637', '9181', 'z', 'h', '2487', 'i', '3779', '2017', '5217', '5013']

A: c, h, i, m, s, z
****
Q: ['n', 'w', '6735', '3427', '6115', 'q', '7851', '3645', 'g', '6825', '6515', '4885', 'z']

A: g, n, q, w, z
****
Q: ['3723', '299', '223', 'w', '9543', 'w', '4395', 'w', 'm', '175', 'y', 'b', 'l', '8315', 'n']

A:
b, l, m, n, w, y
****