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: ['1', 'm']

SOLUTION: 1

PROBLEM: ['z', 'l', 's', '249', 'e', 'h', 'l']

SOLUTION: 2, 4, 9

PROBLEM: ['403', '437', 'n']

SOLUTION:
0, 3, 4, 7