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', 'm', '7071', 'j', '353', 'n', 'a', 'm', '9211', 'i', '9537', 'q', '7669', '869', '8753', '8071', '375', '9971', 'c', 'n', '5851', 'u', '2491', '2697', '2789', '4683', '879', 'q', 'g', 'p', 'd', 'x', 'r', 'i', '8171', '5449', '2477', '1151', 'z', '3845', '1079', 'j', 'n', 'p', '8199']

Ex Output:
a, c, d, g, i, j, m, n, p, q, r, t, u, x, z


Ex Input:
['907', '2407', '1385', '3593', 'x', '4143', '2271', '8361', 'q', '5093', 'd', '257', 'm', 'a', '5751', '7845', '3925', '3517', '7753', 'e', '5803', '2629', 't', 'e', '845', '6157', '9787', '225', 'j', 'j', 'l', '1321', 'k', '2459', 'u', '9113', '3193', 'a', 'j', 't']

Ex Output:
a, d, e, j, k, l, m, q, t, u, x


Ex Input:
['s', 'u', '4827', '5415', 'y', '8429', '4945', 'z', 'g', 'm', '2061', '4367', '1733', 'k', 'm', '7515', 's', 'q', '951', '7953', '2575', '2385', '9207', 'g', '6921']

Ex Output:

g, k, m, q, s, u, y, z