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: ['y', '449', 'g', '345', '167', 'q', 'k']

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

PROBLEM: ['455', '447', 'x', '479', 'b', '267', '339', '29', '267']

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

PROBLEM: ['l', '143', '409', 'k']

SOLUTION:
0, 1, 3, 4, 9