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:
['p', '9641', '8515', '1207', 'd', 'j', '6617', '5529', 'g', 'a', 'o', 'f', 'y', '4993', '4643', '6087', 'n', '3177', 'y', '9471', '1229', '8211', '7079']

Ex Output:
a, d, f, g, j, n, o, p, y


Ex Input:
['j', 's', 'z', 'v', '5401', 'u', '8859', 'i', 'l', 'a', 'p', 'v', 'v', 'o', '3969', '4091', 'y', '6827', '1799', '5163', 'd', 'w', '4795', '5167', 'x', 'q', '2903', '1171', '5279', '449', '7901', 'u']

Ex Output:
a, d, i, j, l, o, p, q, s, u, v, w, x, y, z


Ex Input:
['3093', '8373', '3171', 'i', 'g', '2727', 'k', 'q', '8507', 'o', 'q', 'n', 'm', '1925', '703', '8187', 'e', '9165', 'z', 'z', '3303', 't', '3927', '9083', 'm', 'b', '4927', 'l', '3073']

Ex Output:

b, e, g, i, k, l, m, n, o, q, t, z