Teacher: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.
Teacher: Now, understand the problem? Solve this instance: ['g', 'x', 'v', 'e', '235', 'e', 'm', '367', '7', '131', 'n', '409', '7', 'm']
Student:
0, 1, 2, 3, 4, 5, 6, 7, 9