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: ['499', '493', 'i', '87']

SOLUTION: 3, 4, 7, 8, 9

PROBLEM: ['u', 'r']

SOLUTION: -1

PROBLEM: ['k', 's', 'x', 'a', '487']

SOLUTION:
4, 7, 8