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]: ['7013', '8755', 'u', '9377', 'n', '6997', '507', '8557', '9745', 'g', '3019', '93', 'l', '1219', 'a', '393', '2573', 'q', 'b', '6101', 'e']
[A]: a, b, e, g, l, n, q, u


[Q]: ['i', 's']
[A]: i, s


[Q]: ['5669', 'b', '9129', '3003', 'q', '1045', 'e', 'y', '3203', '9989', 'e', '7801', 'd', '6097', '9271', '2827', '2715', '181', '3779', 'p', '2269', 'l', 'u', '7669', 'c', '6635', '9211', 'o', '1809']
[A]:
b, c, d, e, l, o, p, q, u, y