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:
['4417', 'x', '4641', '885', '8485', 'd', '7057', '8519', 'm', 'i', 'l', '4627', '3069', 'v', '5011', 'u', '6673', 'h', '4541', 'j', '2337', '8175', '4797', 'f', '9109', 'q', 'q']
answer:
d, f, h, i, j, l, m, q, u, v, x


question:
['2047', '4403', 'g', '3017', '1627', 'v', 'r', '2237', '5513', 'o', 'v', '7229', '9801', 'j', '443', 'z', 'q', 'y', '7447', '1659', '3411', '55', '5153', '9921', '2195', '1075', '8187', 'p', 'x', 'h', 'y', 't', 'a', 'r', 'f']
answer:
a, f, g, h, j, o, p, q, r, t, v, x, y, z


question:
['5353', 'a', 'k', '5185', '4259', '3183', 'g', '5717', '9613', 'k', 'f', '1209', 'b', '7115', 'p', '1671', '9119', 'w', '5391', '1809']
answer:

a, b, f, g, k, p, w