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: ['o', 'e', '187', '153', 'a', '253', 'f']

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

PROBLEM: ['i', 'f', '109']

SOLUTION: 0, 1, 9

PROBLEM: ['273', '337', '113', '107', 'm', 'j', '477', 'f', 'c', 'm', 't', 'g', 'w']

SOLUTION:
0, 1, 2, 3, 4, 7