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: ['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: ['k', '413', '321', '209', 'k', '263']

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

PROBLEM: ['i', 'x', '3', '357', '53', '107', '421', 'm', 'l', 'j', '185', 'y', 's', '459', '147']

SOLUTION:
0, 1, 2, 3, 4, 5, 7, 8, 9