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:
['3411', 'a', 'v', 'j', '8925', '909', 'h', 'l', 'r', '1371', 'u', '7789', '4813', 'u', 'q', 'i', '8473', 'n', '7191', 'c', '4641', 'e', '5107', 'q', 'z', 't', '105', 'q']

Ex Output:
a, c, e, h, i, j, l, n, q, r, t, u, v, z


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:
['1761', 'a', '9603', '9829', 's', '4195', 'a', 'n', '7487', 'z', '9395', '2093', '9063', 'c', '3925', '6735']

Ex Output:

a, c, n, s, z