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.

['u', '9249', 'u', 't', 'm', 'm', 'n', 'w', '8617', '2729', 'i', 'l', '2971', '3227', 'b', '9017', '4711', 'i', 't', 'r', 'a', 'a', '1701', '6397', '4535', '9167', '6039', '6111', '849', 'p', '8197', '2645', '5147', 'u', 'l', '7419', 'w', 'w', 'k', 'x', 'c', '3377', '4015', '1297', 'f']
a, b, c, f, i, k, l, m, n, p, r, t, u, w, x

['w', '5341', 'b', '6243', 'v', '877', '1087', '6763', '5241', '3369', '9119', 't', 'v', 'j', '8261', 'o', 'b']
b, j, o, t, v, w

['d', 'u', 'l', 'k', 'j', 'o', '7925', '9857', 'x', '8757', '3991', '6263', 'k', '1465', '2557', '9047', '2639', 'd', '8625', 'r', 'h', '7257', 'n']

d, h, j, k, l, n, o, r, u, x