Hi, thank you for reporting.

I tried to check the interactor and found one possible reason.

In your solution, for the case N > 3, you are assuming that the interactor will reply with CORRECT after the second query and immediately read the value of the next N. However, the interactor still replied with INCORRECT after your second query followed by a numeric string, so the next value of N that you read can be any arbitrary number. Then, you print a string of length N to the interactor, which may be an arbitrarily large string.

The interactor uses cin to read a string in a line, so if you send a very large string to the interactor, it may raise the memory problem. I can prevent this thing from happening in the interactor by limiting the number of characters to read in a line, but doing any changes to the interactor without further testing can be risky, so I decided to leave it as of now.

I suggest you properly handle the CORRECT and INCORRECT replies by the interactor. We apologize for the imperfect interactor.