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]: ['r', 's', '2471', 'n', '635', 'k', '3551', '7041', '8765', '1221', '8439', '7773', '6471', 'u', 'p', '2093', '6479', '1435', '6881', 'a', 'y', 'm', 'r', '1627', 'w', 'k', 'b', '3095', '9059', '285', 'y', 'a', 'm', 'x', '637', 'i', '3407', 'e', 'e']
[A]: a, b, e, i, k, m, n, p, r, s, u, w, x, y


[Q]: ['7777', '6223', 'k', 'k', 'd', '9743', '189', '7705', 'c', '6115', '4275']
[A]: c, d, k


[Q]: ['9375', 'f', 'q', 'a', 'e', '6463', '5331', 't', '31', 'z', '2085', '9977', 's', '9975', '9085', 'q', '9251', '3893', 'f', '7967', '6487', '4629']
[A]:
a, e, f, q, s, t, z