TestAB 1

class A7 {
    int x = 10;
    int y = 20;
}

class B7 extends A7 {
    int x = 30;
    int y = 40;
}

public class TestAB {
    public static void main(String[] args) {
        B7 b = new B7();
        A7 a = new B7();
        System.out.println(b.x + ": " + b.y);
        System.out.println(a.x + ": " + a.y);
        b.x = 5;
        b.y = 6;
        System.out.println(b.x + ": " + b.y);
        System.out.println(a.x + ": " + a.y);
    }
}