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:
['n', 'q', '6461', 's', '8565', '2237', '2071', '8143', '2977', '5511', 'j', 'o', '5793', 'j', 'm', 'n', '8031', 'j', '535', '5001', 's', 'y', '1737']

Ex Output:
j, m, n, o, q, s, y


Ex Input:
['5859', 'x', 'z', 'v', 'l', 'z', 'g', 't', 'x', '341', '7023', '4937', 'b', 'n', 'y', 't', 's', '1369', '4461', 'f', '1315', 'l', '5221', '6583', 'h', 'j', 't']

Ex Output:
b, f, g, h, j, l, n, s, t, v, x, y, z


Ex Input:
['1361', '7749', '6411', 'y', '8957', '8885', '889', '6017', '331', '6403', '1775', '5345', '5453', '3345', '1277', '1215', 'n', '5637', 'z', 'j', 'x', '859', '8635', '5639', '7127', '4923', '603', 'y', '4785', '3377', 'm', 'f', '5391', 'p']

Ex Output:

f, j, m, n, p, x, y, z