public class Main {
    public static void main(String[] args) {
        Person p = new Person("小明", 12);        
        Student s = new Student("小红", 20, 99);       
      // TODO: 定义PrimaryStudent，从Student继承，新增grade字段:    
       Student ps = new PrimaryStudent("小军", 9, 100, 5);     
       System.out.println(ps.getScore());    }
}

class Person {
    protected String name;    
    protected int age;    
public Person(String name, int age) {
        this.name = name;        
this.age = age;   
 }

    public String getName() { return name; }
    public void setName(String name) { this.name = name; }

    public int getAge() { return age; }
    public void setAge(int age) { this.age = age; }
}

class Student extends Person {
    protected int score;    public Student(String name, int age, int score) {
        super(name, age);        this.score = score;    }

    public int getScore() { return score; }
}

class PrimaryStudent extends Student {
    protected int grade;   
    public PrimaryStudent(String name, int age,int score, int grade) {
        super(name, age, score);        
       this.grade = grade;    }
}