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")
   
};

>>23
Atheism is the belief in no god(s), which also can't be proven.  Agnosticism is understanding that neither side can prove their claim without supernatural forces intervening.