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: ['1945', 't', '4477', '4439', '6569', '2021', 'y', 't', '2725', '8947', '6921', '1373', '8107', 'g', 'c', 'w', 'x', 'b', '9117', 'k', '6567', '5073', '2307', 'e', 'b', '7405', 'e', 'x', '1419', 'd', 'o', 'n', 'a', '2647', 'z', '1459', 'n', '6137', 'u', 'b', 'q', '4459']

Answer: a, b, c, d, e, g, k, n, o, q, t, u, w, x, y, z


Question: ['i', '1129', 'f']

Answer: f, i


Question: ['1887', '3777', 'f', '8329', 'f', '9229', 'e', 'n', 's', '9037', '9203', '8229', 'h', '7037', '6417', '1673', '3361', 's', '6703', '9621', '8143', 'j', 'f', '6729', '5675', 'a', '7761', 'e', '4951', '8559', '6747', 'q', '9263', '9591', 'c', 'q']

Answer:
a, c, e, f, h, j, n, q, s