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: ['a', '55', 's', '71', '271', '211']

SOLUTION: 1, 2, 5, 7

PROBLEM: ['p', '231', 'd', 'i', '33', '431']

SOLUTION: 1, 2, 3, 4

PROBLEM: ['g', 'v', 'e', 'r', '77', 'u', 'a']

SOLUTION:
7