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: ['b', 'm', '471']

SOLUTION: 1, 4, 7

PROBLEM: ['385', 'k', 'a', 't', 'o', 'b', 'g', 'u', '319', 'e', '315', '365']

SOLUTION: 1, 3, 5, 6, 8, 9

PROBLEM: ['t', 'j']

SOLUTION:
-1