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:
['o', 'm', '8015', '787', '4787', '1727', 'f', 'e', 'c']

Ex Output:
c, e, f, m, o


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:
['551', '1591', '3295', 'w', '6503', '37', '2483', '1641', 'y', '6209', 'e', 'i', '5673', 'j', 'm', 'n', 'l', 'v', 'n', '1259', '8861', '2113', 'j', '5931', '7703', 'w']

Ex Output:

e, i, j, l, m, n, v, w, y