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: ['g', 'u', 'q', '1375', '9491', 't', 'w', 'c', 'v', 'y', '3169', '1607']

A: c, g, q, t, u, v, w, y
****
Q: ['8315', 'b', '4333', 'f', '6507', '6211', '3475', 'c', 'e', '8039', '661']

A: b, c, e, f
****
Q: ['7247', '1909', '3857', 'v', 'w', '7811', '8289', '4371', '2103', 'u', 'n', '8551', 'o', 'x', 'g', '4085', '215', '585', '679', 'b', 'n', '8147', '1255', 'v', '3655', '4463', 'h', '547', 'q', 'v', '6655', '1855', 'i', '8979', '6759', 'l', 'k', 's', 'd', 'l']

A:
b, d, g, h, i, k, l, n, o, q, s, u, v, w, x
****