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: ['469', 'y', 'j', 'u', '475', 'k', 'k']

SOLUTION: 4, 5, 6, 7, 9

PROBLEM: ['381', '129']

SOLUTION: 1, 2, 3, 8, 9

PROBLEM: ['c', 'm', '469', '301']

SOLUTION:
0, 1, 3, 4, 6, 9