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.

['r', '9489', 'e', 'n', '6323', 'd', '3163', '265', '8587', '7891']
d, e, n, r

['7595', '5303', '3985', 'n', 'w', 's', 'r', 'f', '8237', 'q', 'y', 'f', '3121', '2463', '4597', 'q', '6801', 'f', 'i', '8563', '3267', 'k', '6157', 'f']
f, i, k, n, q, r, s, w, y

['7951', 'o', '99', 'l', '4041', '9749', '9999', 'e', 'q', 'n', 'f', '5823', '9013', 'b', '481', 's', 'r', '6673']

b, e, f, l, n, o, q, r, s