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.

[EX Q]: ['i', 'x', 'n', 'w', '8915', 'd', 'd', 'd', '6025', '7861']
[EX A]: d, i, n, w, x

[EX Q]: ['749', 'r', 'a', 's', 't', '5905', 'm', 'd', '8437', '4583']
[EX A]: a, d, m, r, s, t

[EX Q]: ['t', '1033', '2915', 'c', '4703', 't', 'x', '4195', '8847', 'x', '8099', '8793', '5703', '7449', '6463', '4057', '4233', '9049', 'n']
[EX A]:
c, n, t, x