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: ['o', '61', '475', '457', 'a', 'o', 'z', '227', '415', 'z', 'x', 'y', '73', '205', 'y']

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

PROBLEM: ['f', '463', '169', '175']

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

PROBLEM: ['t', 'l', 's', 'y', 'r', '275']

SOLUTION:
2, 5, 7