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: ['f', '463', '169', '175']

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

PROBLEM: ['473', '449', '357', 'p', 'p', 'e', '377', '77']

SOLUTION: 3, 4, 5, 7, 9

PROBLEM: ['b', 'l', 'm', 'z', '1', 'h', 'a', '375']

SOLUTION:
1, 3, 5, 7