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: ['v', 'q', '139', '79', '149', '469', 'g', '239', '221', 'v', '77']

SOLUTION: 1, 2, 3, 4, 6, 7, 9

PROBLEM: ['s', '443', '239', 't', '99']

SOLUTION: 2, 3, 4, 9

PROBLEM: ['i', '371', '187', '157', 'b', '195', 'y', 'i', '259', '419', 'g', '191']

SOLUTION:
1, 2, 3, 4, 5, 7, 8, 9