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]: ['o', 'm', '8015', '787', '4787', '1727', 'f', 'e', 'c']
[A]: c, e, f, m, o


[Q]: ['n', '6615', 'r', 'q', '3803', '4641', '9775', '7719', 'n', '6571', '2723', '6919', 'e', 'f', '1919', '6963', '2581', 'y', '713', 'w', 'w', 'w', 'l', 's', '3993', '9563', '9365', '9277', '103', '2737', 'y', '6005', '9763', 'p', '261']
[A]: e, f, l, n, p, q, r, s, w, y


[Q]: ['4453', 'x', 'x', 'r', 'n', 'b', 'v', 'n', 's', 'r', '1401', '2295', '8581', 'o', 'j', 'k', '861', '7263', 'c', '8297', '2003', '6935', 'm', 'a', '4791', '2079', '1293', 's', 'e', 'c', 'e', 'f', 'r', '6115', '6545', '1577', 'b', '9747', '7541', '6799', '2943', '6141', 'i', 'b', 'e']
[A]:
a, b, c, e, f, i, j, k, m, n, o, r, s, v, x