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.

['5509', 'b', 'd', '3817', '6429', '8475', '6099', '8209', 'd', '2693', '6935', '7295', 'w', '9827', '3687', 'z', 'h', 'r', 'v']
b, d, h, r, v, w, z