import java.util.Set;
import java.util.HashSet;
//學生類

public class Student {
?? ?public String id;
?? ?public String name;
?? ?public Set courses;

?? ?public Student(String id,String name){
?? ??? ?this.id=id;
?? ??? ?this.name=name;
?? ??? ?this.courses=new HashSet();
?? ?}
}