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]: ['z', 'l', '1759', 'k', '8197', 'v', '931', '2587', '7219', '3455', 'e', '8135', 'm', 'n', 'm']
[EX A]: e, k, l, m, n, v, z

[EX Q]: ['w', '6291', '3939', '9569', 'u', '1635', '3359', '8335', 'n', '2799', '7359', 'k', 'm', '2817']
[EX A]: k, m, n, u, w

[EX Q]: ['n', '5577', '9079', 'u', 'a', '5271', 'd', 'x', 'n', 'j', '9121', '89', 'c', 'a', 'd', 'p']
[EX A]:
a, c, d, j, n, p, u, x