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: ['273', 'b', '461', '419', '349', '301', '365', 'k', '319', 'o']

SOLUTION: 0, 1, 2, 3, 4, 5, 6, 7, 9

PROBLEM: ['459', 'd', '473', 'i', 'l', 's']

SOLUTION: 3, 4, 5, 7, 9

PROBLEM: ['s', 't', '237', 'x', '97', '459', '79', '47', 'g', 'n', 'p', 'k', '257', 'b']

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