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]: ['m', '5005', 'y', 'h', 'w', '3609', 'p', '2539', '3307', 'p']
[EX A]: h, m, p, w, y

[EX Q]: ['4641', '2881', 'c', '4827']
[EX A]: c

[EX Q]: ['4443', 'z', 'm', '9919', '4697', 'a', 'i', 't', '9961', 'o', '1269']
[EX A]:
a, i, m, o, t, z

