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.

Ex Input:
['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']

Ex Output:
a, b, e, i, k, m, n, p, r, s, u, w, x, y


Ex Input:
['q', 'h', 'q', '7185', 'f', 'l', 'r', '3605', 'x', 'i', 'v', '8789', 'u', 'x', 'x', '8315', 'x', 't', 'h', 'o', '4943', '5827', '7677']

Ex Output:
f, h, i, l, o, q, r, t, u, v, x


Ex Input:
['6797', 'i', 'h', '3299', 't', 'i', 'r', '9557', 'o', '6097', 'r', 'q', '767', 'o', '9825', 'a', 'u', 'y', 'v', 'i', 'p', 'm', 'n', '807', 'q', 'r', 'a', '6653', 'f', '7683', 't', '7589', 'r', 'l', 'l', '8673']

Ex Output:

a, f, h, i, l, m, n, o, p, q, r, t, u, v, y