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: ['i', 'b', 'w', '409', 'f', '67', 's', '21', 'y', 'c', '401', 'f', 'k', '319']

SOLUTION: 0, 1, 2, 3, 4, 6, 7, 9

PROBLEM: ['g', '55', '153', '179', 'l', 'k', 'h', '21', '433', 'r', '53', '85', 'f', 'e']

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

PROBLEM: ['439', '495', '379', '163', '87', '215', 'x', 'k', 'c', 's', 'c']

SOLUTION:
1, 2, 3, 4, 5, 6, 7, 8, 9