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:
['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:
['a', 'p', 'y', 'l', 'l']
answer:
a, l, p, y


question:
['j', 'd', 'n', '4325', '8581', '4249', '3947', '2587', '4811', 'l', '257', 't', '6657', '2041', '4871', 'm', '6601', '1119', '481', '7765', '7691', 'u', 'g', 'x', '5671', 'u', 'r', '5703', '4795', '2591', 'o', 'e', '441', '2199', 'z', 'o', '7493', '4251', '7745', '9329', 'p', '3781']
answer:

d, e, g, j, l, m, n, o, p, r, t, u, x, z