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]: ['8975', '7199']
[EX A]: -1

[EX Q]: ['7073', 'd', 'e']
[EX A]: d, e

[EX Q]: ['9483', '501', 'j', 'k', '3103']
[EX A]:
j, k