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]: ['699', 'd', '6027', 'j', 'e', 'c', 't', '9983', '5471', '2649', 't', '2631', 'r', 'h', '293', 'j', '8699', 'p', 'k', '5433']
[A]: c, d, e, h, j, k, p, r, t


[Q]: ['f', '3409', 'i', '4147', '1745', '6007', 'l', 'd', 'i']
[A]: d, f, i, l


[Q]: ['6905', 'f', '4995']
[A]:
f