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:
['g', 'p', '2925', 'n', 'o', 'y', '6381', 'l', '4963', 'g', 'm', 'u', 't', '9389', '3787', '7713', '1251', '779', 'i', 'w', '9869', 'y', 'y', '3881', 'k', 't']

Ex Output:
g, i, k, l, m, n, o, p, t, u, w, y


Ex Input:
['o', '4167', 'b', '1651', '8327', '9219', 'o', 'v', '5841', '6057', 'i', 'q', 'o', 'r', 'a', '7069', 'y', 'h', 'd', '3775', 'j', 't', '3663', '55', '7117', 'e', 'u', 'm', '931', '5777', '8773', '4891']

Ex Output:
a, b, d, e, h, i, j, m, o, q, r, t, u, v, y


Ex Input:
['g', 'v', 'a', 'y', 'q', '2121', 'p', '4509', '819', 'i']

Ex Output:

a, g, i, p, q, v, y