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: ['251', '173', '301', '339', '267', 'p', '347']

SOLUTION: 0, 1, 2, 3, 4, 5, 6, 7, 9

PROBLEM: ['381', '129']

SOLUTION: 1, 2, 3, 8, 9

PROBLEM: ['i', 'q', '21', 'i']

SOLUTION:
1, 2

