public class MyBaseException extends Exception{
	public MyBaseException(){
		super();
	}
	public MyBaseException(String s){
			super(s);
	}
}
class MySubException extends MyBaseException {
	public MySubException(){
		super();
	}
	public MySubException(String s){
		super(s);
	}
}
class MyNextException extends Exception{
	public MyNextException(){
		super();
	}
	public MyNextException(String s){
		super(s);
	}
}