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.

[Q]: ['d', '4377', '9271', '8053', '9519']
[A]: d


[Q]: ['6709', 't', 'n', 'k', '991', 'a', '8899', '3563', '527', 'm', '4599', '6679', 'm', 'x', 'f', 'o', '3275', 'x', '677', 'b', '3329', '3593', '5183', '5753', 'u', '6045', '2607', 'y', '9873']
[A]: a, b, f, k, m, n, o, t, u, x, y


[Q]: ['1913', '3551', '8493', '1999', 'i', '6877', 't', '5927', 'x', '4487', 'e', '3085', 'd', 'e', '3847', 'i', '7655', '5737', 'g', '2885', 'm', '3755', 's', 'p', 'b', '6911', '2017', '8781']
[A]:
b, d, e, g, i, m, p, s, t, x