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.

[EX Q]: ['j', '6675', 'u', 's', '705', '8227', 'f', 'w', 'n']
[EX A]: f, j, n, s, u, w

[EX Q]: ['f', '165', 'm', '9975', '9259', '6505', 'a', 'g', 's', '1127', 'h', 'n', 'c', '6475', 'c', '8657', 'a', '4057', 'm', 'y', 'w', 'm', '6567', '7297', '285']
[EX A]: a, c, f, g, h, m, n, s, w, y

[EX Q]: ['x', '3707', 'w', 'k', '1757', 's', 'm', '9419', 'f', '861', '3191', '1057', 'a', 'x', '6585', 'j', '5467', 's', 'd', '9193', '6265', '9847']
[EX A]:
a, d, f, j, k, m, s, w, x