//Create a superclass.

class A1 {
	int i, j;
	void showij() {
		System.out.println("i and j: " + i + " " + j);
	}
}

//Create a subclass by extending class A1.
class B1 extends A1 {
	int k;
	void showk() {
		System.out.println("k: " + k);
	}
	void sum() {
		System.out.println("i+j+k: " + (i+j+k));
	}
}

public class SingleInhDemo2 {

	public static void main(String[] args) {

		A1 superOb = new A1();
		B1 subOb = new B1();

		// The superclass may be used by itself.
		superOb.i = 10;
		superOb.j = 20;
		System.out.println("Contents of superOb: ");
		superOb.showij();
		System.out.println();

		/* The subclass has access to all public members of
		its superclass. */
		subOb.i = 7;
		subOb.j = 8;
		subOb.k = 9;
		System.out.println("Contents of subOb: ");
		subOb.showij();
		subOb.showk();
		System.out.println();
		System.out.println("Sum of i, j and k in subOb:");
		subOb.sum();
	}
}