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: ['u', 'm', 'n', 'h', 'u']

SOLUTION: -1

PROBLEM: ['f', 'f', '149', '311', '331', 'l', 'u', '349', 'v', 'v', '417', '285']

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

PROBLEM: ['57', 'i', 'b', '171', '285', 'z', '455']

SOLUTION:
1, 2, 4, 5, 7, 8