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: ['149', 'o', '237', 't', 'k', 'w']

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

PROBLEM: ['p', 'p', '91']

SOLUTION: 1, 9

PROBLEM: ['487', '355', 'm', 's', '367', 'n', '203', 'x', 't', 'v', 'd', '251']

SOLUTION:
0, 1, 2, 3, 4, 5, 6, 7, 8