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]: ['h', 'v', '1263', 'y', '3299', 'd', 'a', 'h', 's', '2007', '7597', '1015', 'k', '6643', '6959', 'g', 'u', 'd', '5737', 'n', 'z', 'y', 'b', 'g', '9059', '7349', 'j', 'w', 'i', 'z', 'p', '5809', 'x', '4421', 'g', '6399', '3965']
[A]: a, b, d, g, h, i, j, k, n, p, s, u, v, w, x, y, z


[Q]: ['2697', 's', '8733', 'n', '5871', 'f']
[A]: f, n, s


[Q]: ['x', 'w', 'o', 'u', '257', '57', '2007', 'e', 'o', 'e', 'g', 'n', 'h', 'm', 'h', 'a', 'n', 'q', 'b', '5439', '7991', 'g', 'c', 'r', 'c', '1349', 'd']
[A]:
a, b, c, d, e, g, h, m, n, o, q, r, u, w, x