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.

['7799', '8163', '3389', 'x', 'k', 'm', '6085', 'f', '1131']
f, k, m, x

['o', 'm', '8015', '787', '4787', '1727', 'f', 'e', 'c']
c, e, f, m, o

['z', 'h', 'r', '7909', 'q', 'k', 'j', 'r', 'd', '7027', 'z', '6027', '7601', '6057', '5035']

d, h, j, k, q, r, z