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: ['255', 'u', 's', 'g', '445']

SOLUTION: 2, 4, 5

PROBLEM: ['25', 'n', 'n', '481', 'w', '91', '251']

SOLUTION: 1, 2, 4, 5, 8, 9

PROBLEM: ['187', '295', 'n', '203', '323', '125', '215', '287', '361', '37', '475', '357', '195', '481', '157']

SOLUTION:
0, 1, 2, 3, 4, 5, 6, 7, 8, 9