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.

['s', 's', '6581', 'e', '7355', '1315']
e, s

['8315', 'b', '4333', 'f', '6507', '6211', '3475', 'c', 'e', '8039', '661']
b, c, e, f

['6823', 'n', '7869', 'v', '6129', '8387', '1257', '8271', '311', '9151', '6589']

n, v