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: ['c', '155', '61']

SOLUTION: 1, 5, 6

PROBLEM: ['p', 'n', 'c', '113', '105', '423', 'k', 'a', '211', 'k', '91', '389']

SOLUTION: 0, 1, 2, 3, 4, 5, 8, 9

PROBLEM: ['f', '257', 'w', '465', 'i', 'h', 'l', '37', 'c', 'n']

SOLUTION:
2, 3, 4, 5, 6, 7