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: ['a', 'n', '423', 'y', 'y', 'u', '55', 'y', '295', '73', 't', 'p']

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

PROBLEM: ['o', '235', '479', 'e', '199', 'c', '25', '59', 'g', '415', '201', '129', 'a', 'i', 'c']

SOLUTION: 0, 1, 2, 3, 4, 5, 7, 9

PROBLEM: ['m', '427', '477', '67', 'k', '87', 'e', 'i', '473', 'o', '139']

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