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: ['q', 'u', '199', 'v', '249']

SOLUTION: 1, 2, 4, 9

PROBLEM: ['411', '367']

SOLUTION: 1, 3, 4, 6, 7

PROBLEM: ['m', '337', 't', 'p', '321']

SOLUTION:
1, 2, 3, 7