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.

['2247', 'w', 'h', '4675', '6153', 'f', '6029', 'o', 'd', 'j', 'z', 'y', 'i', '6899', '3917', 'u', '6447', '6405', 'a', '1705', '8585', 'v', 'f', 'r']
a, d, f, h, i, j, o, r, u, v, w, y, z

['s', 'w', '8949', '4025']
s, w

['t', '6155', 'd', '689', 'd', '851', '3383', 'i', 'x', '3793', 'o', 'x', '5225', '3933', '1833', '9349', '2579', '4561', '7895', 'a', 'r', '7299', 't', '6523', 'j', '6123', '6843', '8637', '8867', '8105']

a, d, i, j, o, r, t, x