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: ['357', '269', '105', '315', 'c', '301', 'v', '441', '415', 't', 'a', 'o', 'u', '23', 'n']

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

PROBLEM: ['437', '377']

SOLUTION: 3, 4, 7

PROBLEM: ['95', '205', 'c', '101']

SOLUTION:
0, 1, 2, 5, 9