TASK DEFINITION: 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.
PROBLEM: ['25', 'n', 'n', '481', 'w', '91', '251']

SOLUTION: 1, 2, 4, 5, 8, 9

PROBLEM: ['363', '455']

SOLUTION: 3, 4, 5, 6

PROBLEM: ['p', '489', '437', '61', 's', 'b', 'q']

SOLUTION:
1, 3, 4, 6, 7, 8, 9