怎么改都不行一只报错

父类：

package imooc;

public abstract class Shape {

public abstract void a();

public abstract void b();

}

子类

package imooc;

public abstract class Mea extends Shape {

@Override

public void a() {

// TODO Auto-generated method stub

System.out.println("22");

}

@Override

public void b() {

// TODO Auto-generated method stub

System.out.println("ss");

}

}

测试：

package imooc;

public class Test {

public static void main(String[] args) { 

// TODO Auto-generated method stub

Shape rr=new Mea();

}

}