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: ['6027', 'v', 'b', 'l', '7853', 'r', 'y', '2919', '3831']

A: b, l, r, v, y
****
Q: ['9627', '9879', '5421', '4755', '1533', '6727', 't', '7641', 'd', '3929', 'h', '3989', '8441', 'k', 'p', '2653', 'm', 'b', 'i', '3431', '4907', '5687', 'g', 'h', '9185', '5051', 'k', '7135', '709']

A: b, d, g, h, i, k, m, p, t
****
Q: ['a', 'e', '5593', 'l', '2227', '7217', 'p', 'x', 'q', '5457', '9103', '603', '4981', 'b', '7837', '4357', '4045', 'q']

A:
a, b, e, l, p, q, x
****