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:
['9627', '9879', '5421', '4755', '1533', '6727', 't', '7641', 'd', '3929', 'h', '3989', '8441', 'k', 'p', '2653', 'm', 'b', 'i', '3431', '4907', '5687', 'g', 'h', '9185', '5051', 'k', '7135', '709']

Ex Output:
b, d, g, h, i, k, m, p, t


Ex Input:
['1121', 'j', '1433', 'g', 'l', '1479', '1699', 'j', 'a', '8507', 'd', 'a', '5229', 'k', 'x', '4549', 'e', 'p', '1367', 'u', 'd', '785', '215', 'e', 'f', 'a', '101', '7575', '7965', 'p', 'i', '5637', '1005', 'i', 'y', '181', 'r']

Ex Output:
a, d, e, f, g, i, j, k, l, p, r, u, x, y


Ex Input:
['7167', 'c', '3539', 'm', 'i', 'x', '3523', 'w', 'v', 'v', 'l', 'q', '203', '4957', 'h', 'z', 'o', '877', 'i', '3467', 'w', 'y', 'l', '133', '7497', '9237', 'f']

Ex Output:

c, f, h, i, l, m, o, q, v, w, x, y, z