instruction:
In this task, you are given an input list A. You need to extract and sort the unique digits used in the list in ascending order. Return -1 if there is no digit in the list.
question:
['q', 'p', 'y', 'p', 'k', 'r', '481', 'v']
answer:
1, 4, 8


question:
['y', 'v', '311', 'f', '273']
answer:
1, 2, 3, 7


question:
['g', '159', '371']
answer:

1, 3, 5, 7, 9