I thought that I would go until the end of the input and then go back in the middle and insert a '#'. Then I know how to solve this problem. The input will have as first char a special symbol |_| and will end with this symbol too. So an example of accepted input would be this one:Code:w is in {a, b}^*I do not know how to go back in the middle or how to measure the length of the input. I do not know however the tools to do that! Any idea?Code:|_|abaaba|_|