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]: ['g', 'p', '2925', 'n', 'o', 'y', '6381', 'l', '4963', 'g', 'm', 'u', 't', '9389', '3787', '7713', '1251', '779', 'i', 'w', '9869', 'y', 'y', '3881', 'k', 't']
[A]: g, i, k, l, m, n, o, p, t, u, w, y


[Q]: ['j', 'r', 'z', 'f', '1485', '2419', 't', 'd', '6023']
[A]: d, f, j, r, t, z


[Q]: ['7747', '2203', '821', 't', 'b', '185', '4953', 'j', '6215', 'w', '4173', 'e', '3415', 'm', '1209', '6713', 'k', 'k', 'q', '7037', '6715', '6115', 'u', '2281']
[A]:
b, e, j, k, m, q, t, u, w