instruction:
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.
question:
['1799', '6409', '9257', '5923', 'm', 'j', '2565', '715']
answer:
j, m


question:
['5075', '9169', '4659', '7605']
answer:
-1


question:
['9739', '9735', '2361']
answer:

-1


