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: ['215', '391', '251', '177']

SOLUTION: 1, 2, 3, 5, 7, 9

PROBLEM: ['z', 'z', '273']

SOLUTION: 2, 3, 7

PROBLEM: ['i', '65']

SOLUTION:
5, 6