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: ['43', '479', '317', 'w', '475', '255', '3', 'x']

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

PROBLEM: ['n', 'm', 'u', '267']

SOLUTION: 2, 6, 7

PROBLEM: ['415', 'b', 'b', '105', 'r', 'm', 'z', '73']

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