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: ['353', 'y', 'a', 'g', '141', '97', '457', '297', '25', 'g', '131', 'u', '303', '39', 'p']

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

PROBLEM: ['455', '447', 'x', '479', 'b', '267', '339', '29', '267']

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

PROBLEM: ['z', '21', 's']

SOLUTION:
1, 2