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:
['311', '147', 'a', '149', 'h']
answer:
1, 3, 4, 7, 9


question:
['7', 'u', 's', '75', 't', 'o']
answer:
5, 7


question:
['s', 'u', '429', '479', '249', '397']
answer:

2, 3, 4, 7, 9