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:
['t', 't', 'p', '3245', 'x', 'g', 'i', 'u', '2599', '8613', 't', 'v', 'p', '5635', 'y', '9567', '5193', '8617', 'q', 'f']

Ex Output:
f, g, i, p, q, t, u, v, x, y


Ex Input:
['c', 'a', 'p', 'p', '4203', '1587', '2953', '9809', '99', '5821', 't', 'i', '4213', '1809', 's', 'l', 'i', 'b', '9233', '3983', '7713', '1807', 'k', 'f', '7825', '5491', 'o', '1347', 'u', 'h', '3967', 'u', 'g', '6775', '1069', '9211', 'i', '3369', 'r']

Ex Output:
a, b, c, f, g, h, i, k, l, o, p, r, s, t, u


Ex Input:
['973', 'a', '3463', 'f', '7945', '6447', 'z', 'i', 'q', 'd', '323', '713', 'p', '451', 'e', '689', 'c', 'm', '159', 'b', 'w', '4731', 'q', 'r', 'b', 't', '6733', '9465', 'l', '6077']

Ex Output:

a, b, c, d, e, f, i, l, m, p, q, r, t, w, z