// https://www.hackerrank.com/challenges/java-inheritance-1/problem

public class JavaInheritanceI {

public static void main(String[] args) {

}

private static class Animal {

public void walk() {

System.out.println("I am walking");

}

}

private static class Bird extends Animal {

public void fly() {

System.out.println("I am flying");

}

public void sing() {

System.out.println("I am singing");

}

}

}