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]: ['4009', 'y', '9077', 'p', 'q', '6711', '6443', '5491']
[EX A]: p, q, y

[EX Q]: ['4925', '9943', '7935', '4387', '2449', '5797', 'i', '1517', 'w', 'e', '9525', 'y', 't', 'e', '2793', 'v', '9897', '8709', '7247', 'o', 'f', '5549', 'q']
[EX A]: e, f, i, o, q, t, v, w, y

[EX Q]: ['8641', 't', 'l', '7989', '7037', '9705', '6453', 'm', '8103', '8047', 'k', '5851', 'b', '2915', '5405', '3647', 'c', '7627', 'p', 'l', '1437']
[EX A]:
b, c, k, l, m, p, t