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:
['u', 'o', 'b', 'b', '5873', 'w', 'v', '4171', '7957', '3501', '2563', 'l', 'q']

Ex Output:
b, l, o, q, u, v, w


Ex Input:
['4637', 'f', '2639', '8623', 'w', 'e', 'k', '5503', 'x', '6633', '7553', '1455', 'u', '1773', 'r', 'u', '1489', 'u', '1303', '9683', 'z', '565', '7041', 'x', 'z', '9431', 'k', 'v', 'j', 'z', '5469', '5665', '4089', '4951', '8263', '5675', '4095', '7745', 'z', '2437', 'd', 'e', 'w']

Ex Output:
d, e, f, j, k, r, u, v, w, x, z


Ex Input:
['t', '3381', '9991', '3439', 'a', '9489', '4227', '977', 'z', 'i', '4973', '9659', '2969', '9083', '2979', '3707', '2649', '6209', '7567', '9279', 'o', 's', 'h', 'o', 'f', '6601', '3335', 'n', '4507', '7195', '5737', 'f']

Ex Output:

a, f, h, i, n, o, s, t, z