I read this task 13 again... But I don't understand one thing: for example, we have a number ...9898989898989898. This number can be written (98), (89)8 and (98)98. Also (9898) is the same number. As I understand, we can use only (98) in output, but what's about input data? Numbers such (9898) and (999) can not be there, i hope.
What do you think about it?

For my AC solution it does not matter