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: ['p', 't', '211', 'r', '439', 'h', 'g', 'c', '299', '371']

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

PROBLEM: ['y', '449', 'g', '345', '167', 'q', 'k']

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

PROBLEM: ['r', 'o', '369', '341', 'u', '81', '133', '53', '201', '31', '21', '321', '337', '115', 'c']

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