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: ['159', 'y', '369', 'r', '341', '23', 's', '209', 'l', 's', '473']

SOLUTION: 0, 1, 2, 3, 4, 5, 6, 7, 9

PROBLEM: ['m', 'n', '481', 'a', '343', '19', 'l', 'l', '477', '71']

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

PROBLEM: ['m', 'o', 'm', '231', 'p', 'z', 'l', '267', '457']

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

