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:
['2293', 'p', '9787', '7241', '8689', 'u', '3141', 'h', 'c', 'b', 'f', 's', '319', 'c', 'p', '6909', 'p', 'f', '1717', 'd', '2285', 's']

Ex Output:
b, c, d, f, h, p, s, u


Ex Input:
['6175', '9441', '7127', '5979', 's', '1367', 'e', 'm', '7083', '1787', '8375', '2851', '3475', 'r', '697', 'g', 'z', 'm', '4207', 'c', '7971', 'z', '9339', 'd', 's', '3507', '9003', 'i', 'y', 'w', 'j', 'i']

Ex Output:
c, d, e, g, i, j, m, r, s, w, y, z


Ex Input:
['r', 'g', 'u', 'f', '1239', 'j', '9427', '4169', '5453', '7409', 's', 'h', '3975', '9277', 'u', 'a', '5853', '6191', 'o', '549', 'f', 'r', '8063', '2391', '6741', '5845', '6951', 'o', 'k', 'y', '5869', '797', '2615', '7221']

Ex Output:

a, f, g, h, j, k, o, r, s, u, y


