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]: ['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']
[EX A]: a, b, f, k, m, n, o, t, u, x, y

[EX Q]: ['f', '7573', '2067', 'n', '3671', '7969', '7889', '4893', '6501', 'l', 'y', '4331', 'a', 'e', '2081', '3863', 't', 'j', '7921', 's', '7203', '7797', 'f', '4279', '1299', '987', '5003', '9071', '9559', '6061', '1889', '2653', 'm', 'w', '665', '7343', '9763', 'r', '6343', '9393', '9289']
[EX A]: a, e, f, j, l, m, n, r, s, t, w, y

[EX Q]: ['2209', 'j', 'm', 'n', '8153', 'i', '9975', 'l', '3159', 'y', 'r', '4829', '1401', 'j', '2189', '39', 'm']
[EX A]:
i, j, l, m, n, r, y