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:
['f', '9027', 'z', '9601', 'w', '7747', '1135', 'j', '1871', 'd', 'u', 'f', 'd', 'x', 'k', '2009', 't', '4625', 'm', '1619', 'm', 'm', '3107', 'x', '3957', '2495', 'j', '201', 'a', '4635', 'r', '7407', 'b', 'r', 'z']

Ex Output:
a, b, d, f, j, k, m, r, t, u, w, x, z


Ex Input:
['u', 'r', '5207', '8403', '2811', 'q', '5121', '9795', 'f', 'r', '8163', '3771', 'a', '6867', '6737', 'v', 'b', '5109', 'q', 't', 'v']

Ex Output:

a, b, f, q, r, t, u, v