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', 'w', '401', 't', 'g', 'h', 'g', '8073', '9597', '1347', '7835', '5007', '977', 'p', '7679', 'b', '4883', '4931', '999', 'r', '1181', 'x', '2063', 'l', 'w', 'i', 'l', 'x', 'i', '9057', '5007', 'w', '743', '1635', 'y', 'f', '9227', 'z', '5227', 'd', '7129', 'k', '7657']

Ex Output:
b, d, f, g, h, i, k, l, p, r, t, u, w, x, y, z


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:
['r', '63', '3113', 'x', 'h', '2049', 'p', '8211', '6431', '9843', 'g', '2805', '4417', '2531', '7151', 's', '5903', '6025', '7925', 'c', 'h', 'g', '1463', '6651', '2313', '673', 'g', '7585', '8631', 'j', '9177']

Ex Output:

c, g, h, j, p, r, s, x