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:
['4041', 'l', 'g', '9571', '9295', '1395', 'l', 'p', 'f', 'w', 'g', '1721', '2421', 'w', 'z', '2235', 'p', '7851']

Ex Output:
f, g, l, p, w, z


Ex Input:
['8739', 'v', 'm', '6277', 'l', 's', '109', '8057', '3835', 'd', 'u', 'f', 'w', 'd', 'p', '7705', '3643', '4455', 'u', 'p', 'u', '9407', 'g', 'w', '595', 'z', '6827', '6879', 'w', 'w', '6973', 'm', 'e', '1553', 'v', '3529', '8953', '3903', '5713', '8249', 'e', '1113', 'b', 't', 'r']

Ex Output:
b, d, e, f, g, l, m, p, r, s, t, u, v, w, z


Ex Input:
['1197', '4357', 'k', 'e', 'w', 'c', 'u', '977', 'w', 'v', '6961', 't', '2217', 'd', 'q', 'n', 'f']

Ex Output:

c, d, e, f, k, n, q, t, u, v, w