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:
['s', 'u']

Ex Output:
s, u


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:
['z', 'u', 'd', 'g', 'o', 'p', 'v', '4853', 'm', '4149', '1267', '2041', 'f', '2857']

Ex Output:

d, f, g, m, o, p, u, v, z