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]: ['57', 'j', 'n', '877', 'u', 'w', 'j', 'f', '8977', 'h', '469', '9417']
[A]: f, h, j, n, u, w


[Q]: ['2593', '1835', '5089', 'v', '9723', 'f', '9279', '4257', '2175', '655', 'q', 's', 'v', 'j', 'm', '4471', '6419', '1685', '2793', 'x', '509', 's', '4833', '2125', 'b', '6379', '1075']
[A]: b, f, j, m, q, s, v, x


[Q]: ['5443', 'p', 't']
[A]:
p, t