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', 'k', 'o', 'c', 'p', '301', 'o']

SOLUTION: 0, 1, 3

PROBLEM: ['345', 'h', '9']

SOLUTION: 3, 4, 5, 9

PROBLEM: ['237', 'z']

SOLUTION:
2, 3, 7