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.

['315', '9975', '3013', 's', '6131', 'e', 'e', 'u', 'a', '1729', 'g', 't', 'y', 'f', '7523', 'e', 'g', '489', 'm', 'p', 'f', 'e', '2077', 'e', 'g', 'c', 'l', '6389', 'k', 'b']
a, b, c, e, f, g, k, l, m, p, s, t, u, y

['t', 'u', 'y', 'y', 'b', 'x', 'q', '3713', '2679']
b, q, t, u, x, y

['k', '397', '6177', '8227', '2219', '2501', 'q', 'n', 'y', '5827', '2561', 'p', 'p', 'v', '9265', '8583', '7147', '8083', 'l', 'h', '1039', 'm', 's', 'l', 'x', 'd', '1975', '9221', '2541', 'x', 'f', 'z', '5339']

d, f, h, k, l, m, n, p, q, s, v, x, y, z