public class this1
{
    public int x;
    public void print_x(){
        int x=99;
        System.out.println(this.x);
        System.out.println(x);
    }
    public this1(){
        this.x=-1;
    }

    public this1(int x){
        this.x=x;
    }
    public static void main(String[] args)
    {
        this1 ob = new this1(1818);
        ob.print_x();
    }
}

---------------------------
public class this2 extends this1
{
    public int y;
    public void print_a(){
         System.out.println(x);
         System.out.println(y);
    }
    public void print_x(){
        System.out.println("x="+x);
        System.out.println("y="+y);
    }
    public this2(){
        this(-1,-1);
    }
    public this2(int x,int y){
        this.x = x; this.y=y;
    }
    public static void main(String[] args)
    {
        this2 o = new this2();
        o.print_x();
        System.out.println("----------------");
        o.print_a();
    }
}