public class Mono {
    String name = "";

    @Override
    public String toString(){
        return name;
    }
}

class Momo extends Mono {
    Momo(){
        name = "momo";
    }
    Momotaro bornMomotaro(){
        return new Momotaro();
    }

}

class Kibidango extends Mono {
    Kibidango(){
        name = "kibidango";
    }
    

}