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:
['p', '9641', '8515', '1207', 'd', 'j', '6617', '5529', 'g', 'a', 'o', 'f', 'y', '4993', '4643', '6087', 'n', '3177', 'y', '9471', '1229', '8211', '7079']

Ex Output:
a, d, f, g, j, n, o, p, y


Ex Input:
['w', 'o', 'l', '1857', 's', 'q', 'j', 'e', '5945', 'g', 'l', '9563', 'e', 'u', '7633', '7977', '4943', 'y', '5621', 'f', '1653', 'c', 'l', '2843', '2125', '7731', '5257', '5667', 'b', 'b', '5765', 'a', 't', '8163', '9785', '5385']

Ex Output:
a, b, c, e, f, g, j, l, o, q, s, t, u, w, y


Ex Input:
['k', 'f', '5119', 'p', 't', '8701', '1157', '3881', '5867', 'i', 'i', '3891', '1105']

Ex Output:

f, i, k, p, t