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: ['475', '19', 'k', '307', '417']

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

PROBLEM: ['421', '99', '115', 'x']

SOLUTION: 1, 2, 4, 5, 9

PROBLEM: ['443', 'f', 'z', 'u', 'n', '485', '179', '127', 'w', '153', '197', '339', 'a', '235', 'c']

SOLUTION:
1, 2, 3, 4, 5, 7, 8, 9