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: ['h', '281', 'x', '471']

SOLUTION: 1, 2, 4, 7, 8

PROBLEM: ['99', 'p', 'v', '49', 's', '279', 'v', '287', '355', 'o', '131', 'd', 'b']

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

PROBLEM: ['v', 'd', 'b', '177', '23', '227', '475', '371', 'r', '235']

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