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: ['o', 'm', '8015', '787', '4787', '1727', 'f', 'e', 'c']

A: c, e, f, m, o
****
Q: ['8739', 'v', 'm', '6277', 'l', 's', '109', '8057', '3835', 'd', 'u', 'f', 'w', 'd', 'p', '7705', '3643', '4455', 'u', 'p', 'u', '9407', 'g', 'w', '595', 'z', '6827', '6879', 'w', 'w', '6973', 'm', 'e', '1553', 'v', '3529', '8953', '3903', '5713', '8249', 'e', '1113', 'b', 't', 'r']

A: b, d, e, f, g, l, m, p, r, s, t, u, v, w, z
****
Q: ['k', 'y', 'a', 'h', '2517', '7171', 'b', '5311', '4757', 'l', '3053', 'v', '59', 'h', 'm', 'd', 'q', 'e', 'b', '1705', '609', '923', '2787']

A:
a, b, d, e, h, k, l, m, q, v, y
****