public class Exercise {
    public static void main(String [] args) {
	A a = new A();
	B b = new B();
	C c = new C(10);

	a.m(3);
	b.m(3);
	c.m(3);
	
	a.print();
	b.print();
	c.print();
    }
}

class A {
    private int x;

    // constructor 
    public A() {
	x = -10;
    }

    public void m (int y) {
	x = x + y;
    }

    public void print() {
	System.out.println("x = " + x);
    }
}


class B extends A {
    protected int y = 0;

    public void m(int z) {
	y = y + z;	
	super.m(y);
    }
}


class C extends B {
    private int z;

    public C(int w) {
	z = w;
	y = 5;
    }  

    public void print() {
	super.print();
	System.out.println("y = " + y + " z = " + z);
    }   
    
}