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.

['4857', 'z', '313', '7813', '9935', 'o', 'w', 'i', 'x', 'o', 'e', 's', 'a', 'p', 'i', 'v', 'x', '6743', 'p', '435', 'u', 'a', 'h', '607', '2491', '6159', 'u', '7761', '6197', '3449', '3459', 'e', 'g', '8731', '335', '2883', '3941', 'n', '1881', 'y', 'j', '8189', 'k', '7593', '2747']
a, e, g, h, i, j, k, n, o, p, s, u, v, w, x, y, z

['f', '217', '449', 't', 'j', '4097', '5561', '8317', '647', 'u', 'b', '7833', 'r', '9011', 'z', '2753', '2183', 'z', 'o', 'g', '7541', 'b', '8795', '327', 'v', 'e', 't', 'l', '4909', 'k', '7681', 'r']
b, e, f, g, j, k, l, o, r, t, u, v, z

['5913', 'u', '1383', 'a', '7947', 'x', 'n', 'l', 'a', 'z', 'u', '1079', 'm', 'o', 'a', '9717', 'q', 'd', 'h', '9327', 'x', '6643', '3289', '9661', '8123', 'f', 'f', 'o', '1943', '2455', 'w', 'p', 'j', '5013', '4301', 'j', 'w', 'o', 'j', 's', 'e']

a, d, e, f, h, j, l, m, n, o, p, q, s, u, w, x, z