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.

['7595', '5303', '3985', 'n', 'w', 's', 'r', 'f', '8237', 'q', 'y', 'f', '3121', '2463', '4597', 'q', '6801', 'f', 'i', '8563', '3267', 'k', '6157', 'f']
f, i, k, n, q, r, s, w, y

['p', '5229', '7521', 'y', 'n', 'u', 'c', '4047', '781', 'a', '4707', '7149', 'j', 'm', 't', '515', '7691', 'h', '4879', 'j', '6593', 'n', 'p', '2949', '1343', 'y', '2629', 'p', 'b', 'b', '2861', 'a']
a, b, c, h, j, m, n, p, t, u, y

['b', 'v', 'a', 't', '7751', 't', '427', '6065', 'd', 'j', 'v', 'k', 'n', 'v', 'y', 'r', '4703', '3597', 'f', 'n', 'l', '2933', 't', 'g', '3289', 'j', 'n', 'n', '8289', 'j', 'q', 'f']

a, b, d, f, g, j, k, l, n, q, r, t, v, y