You will be given a definition of a task first, then an example. Follow the example to solve a new instance of the task.
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.

['q', '31', 'a', 'd', '53', '85', 'p', '77']
Solution: 1, 3, 5, 7, 8
Why? Here, the numbers in the list are '31', '53', '85' and '77', and the unique digits used in the list are '1, 3, 5, 7, 8' in ascending order.

New input: ['169', 'g', '409', '369', 's', 'k', 'i', 'q', '491', '51']
Solution:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
0, 1, 3, 4, 5, 6, 9