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]: ['o', '1099', 'r', '8995', 'o', '2909']
[A]: o, r


[Q]: ['j', 'p', '8333', '8079', '4703', '7089', '8859', 'b', 'y', 'g', '7971', '6999', '2011', 'k', 'e', '9609', '4179', '3993', 'u', '3957', '6313', '4229', 'k', '5963', 'e', 'y', 'r', 'e', 'a', '2213', 'e', 'i', 'f', '7979', 'r', 'a', 'h', 'e', 'n']
[A]: a, b, e, f, g, h, i, j, k, n, p, r, u, y


[Q]: ['i', '2267', 's', '1827', '1273', 'y', '3971', 'm', '4283', 'p', '9797', 'x', 'k', 'j', '6005', 'f', '3923', 'm', 'm', 'j', '9393']
[A]:
f, i, j, k, m, p, s, x, y