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.

['7367', '9757', '9431', 'h', 'a', 'k', '5833', '6237', 'g', '3585', '8665', 'g', '7517', '1561', 'p', 'p', '1307', '3325', 'q']
a, g, h, k, p, q

['j', '1733', 'p', '6741', '7933', '8943', '733', 'x', '1107', 'z', '1719', '7653', 'y', 'z', '6563', 'p', '4615', 'j', '4489', 'h', 'w', 'y', 'p', 'c', '7949', 'k', 'm', 'r', '9427', '7243', '9777', 'j', '323', '4095', 't']
c, h, j, k, m, p, r, t, w, x, y, z

['b', '2737', 'r', '9951', 'u', 'm', 'j', 'f', '3331', '8741', '6261', '9613', 'j', '5043', '2891', '4001', '4845', 'r', 'b', 'a', '6177', 'y', '5467', 'y', '727', 't', '5131', '3367', 'o', '3493', '5689', '879', '7475', '545', 'x', 'w', 'q', 't']

a, b, f, j, m, o, q, r, t, u, w, x, y