instruction:
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.
question:
['j', 'p', '8333', '8079', '4703', '7089', '8859', 'b', 'y', 'g', '7971', '6999', '2011', 'k', 'e', '9609', '4179', '3993', 'u', '3957', '6313', '4229', 'k', '5963', 'e', 'y', 'r', 'e', 'a', '2213', 'e', 'i', 'f', '7979', 'r', 'a', 'h', 'e', 'n']
answer:
a, b, e, f, g, h, i, j, k, n, p, r, u, y


question:
['o', '4167', 'b', '1651', '8327', '9219', 'o', 'v', '5841', '6057', 'i', 'q', 'o', 'r', 'a', '7069', 'y', 'h', 'd', '3775', 'j', 't', '3663', '55', '7117', 'e', 'u', 'm', '931', '5777', '8773', '4891']
answer:
a, b, d, e, h, i, j, m, o, q, r, t, u, v, y


question:
['m', 'h', '5831', 'u', '835', 'p', '995', 'l', 'h', '8167', '1245', '891', 'i', 'q', '9673', 'n', '7035', '7869', '4157', 'o', 'f']
answer:

f, h, i, l, m, n, o, p, q, u