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.

Q: ['m', '7517', '9361', '9567', '8785', 'k', '5699', '3585', 'v', '1913', '1651', 'g', 'p', '2731', 'q', 'h', '467', 'r', '1091', '9801', 'a', '6645']

A: a, g, h, k, m, p, q, r, v
****
Q: ['g', 'h', 'g', 'g', 's', 'h', '2849', '2705', '1185', 'x', '5789', '8221', 'e', 'x', 'g', 'b', '4903', 'q', '1563', 'r', 'k', 't', '9047', 'p', 'p', '9397', 'u', '7473', 'f', 'o', 'y', '1957', '1039', '9905', 'i', '4829', 'q', 'w', 'k', 'p', 't', '563', 'g', 'l']

A: b, e, f, g, h, i, k, l, o, p, q, r, s, t, u, w, x, y
****
Q: ['a', '6133', 'e', '6147', 'l', 't', 'n', 'u', 'm', 'j', 'm', '3963', '4437', '1005', '7067', '957', 'z', '8399', 'w', 'y', 'w', '2423', '9059', '3741', '2007', 'j', '6277', 'h', 'f', '5051', '7967', '2473', '699', 'j', 'x', 'z', 'o', 'y', 'f', 'n', 'e', 'd', '9211']

A:
a, d, e, f, h, j, l, m, n, o, t, u, w, x, y, z
****