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: ['345', 'k']

SOLUTION: 3, 4, 5

PROBLEM: ['477', 'a', 'n', 'r', '457', 'g', 'c']

SOLUTION: 4, 5, 7

PROBLEM: ['57', '285', '359', 'z', '301', '213', '365', 'n']

SOLUTION:
0, 1, 2, 3, 5, 6, 7, 8, 9