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: ['k', '413', '321', '209', 'k', '263']

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

PROBLEM: ['243', '125']

SOLUTION: 1, 2, 3, 4, 5

PROBLEM: ['223', '55', 'l', '461']

SOLUTION:
1, 2, 3, 4, 5, 6