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]: ['d', '1625']
[A]: d


[Q]: ['q', 'o', '1205', '4429', '6301', 'e', '2857', '5075', '5121', 'p', 'b', '5801', 'a', 'm', 'j', 'p', '1279', '7011', 'x', '2557', 'k', 'v', 'b', 'u', 'w', 'n', '1689', 'o', '1583', 'w', '6403', 'p', '6397', 'e', '823', '5699', 'd', '3399', 'd', 'b']
[A]: a, b, d, e, j, k, m, n, o, p, q, u, v, w, x


[Q]: ['m', '6537', '4063', '6413', 'k', 'd', '2479', 'p', '2251', 'q', '7079', 'r', 'd', 'p', '3347', '1391', '9847', '4487', 'u', '6951', '5285', '5837', '6747', 'r', 's', 'c', 'x', 'b', 'q', 'y', 'd', '331', '679', 'v', '1919', 'f', 'p', '1267', '3151']
[A]:
b, c, d, f, k, m, p, q, r, s, u, v, x, y