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: ['t', 'p', 'u', 'a']

SOLUTION: -1

PROBLEM: ['m', 'n', '481', 'a', '343', '19', 'l', 'l', '477', '71']

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

PROBLEM: ['191', '71', '191', 'l', 'v', 'm', 'a', '195', 'a']

SOLUTION:
1, 5, 7, 9