C++ Exception Class

I have to write/fix this class for an exception in a tic tac toe prompt game, it has to throw an error whenever 0>x>8

Any of you brilliant motherfuckers want to help?

#ifndef illegalmoveexception
#define illegalmoveexception

#include <stdexcept>
#include <string>

using namespace std;
class illegalmoveexception : public illegal_move_exception
{
public:
    illegalmoveexception();
    : illegal_move_exception("invalid move")
   
};

>>30
Agnosticism — Lol u guize. I don't believe there's a cat in that box, but I don't want to say so.
Agnosticism - I have no idea if there's a cat, or anything in the box, nor do I give a fuck about it, so I'm not going to make assertions which cannot be proven.