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:
['r', 'y', 'c', '3211', '9245', '8459', '8521', '5781', 'w', 's', 'd', '5299', 'a', 'y', 'g', 'm', '6435', '8605', 'e', 'h', '6871', 's', '387', 'l', '5829', 'e', 'd', '9545', '2945', 'k', 'v', 't', '8449', '2199', 'm', '2599', '1489', '6623', 'x', 'l']

Ex Output:
a, c, d, e, g, h, k, l, m, r, s, t, v, w, x, y


Ex Input:
['l', '6819', '1029', '2925', '2361', '5545', '2151', '2681', 'f', 'p', '1263', '2875', 'b', '4665', 'f', 'g', 'p', '4829', '8453', 'z', 'l', '4219', '7517', '25', 'a', '5099', '3693', 'i', '1815', '1541', 'g', '7665']

Ex Output:
a, b, f, g, i, l, p, z


Ex Input:
['u', '6477', 'q', 'x', '8521', '389', 's', '6979', 'g', '645', '5103', '3389', '5467', '145', '9347', 'g', 'd', 'f', '4249', 'f', '2297']

Ex Output:

d, f, g, q, s, u, x