public class Duck extends Animal implements Walkable, Swimmable
{
    public Duck(String name) 
    {
        super(name);
    }

    @Override // interface Walkable
    public void walk() 
    {
        System.out.println(getName() + " (a duck) is walking.");
    }
    
    @Override // interface Swimmable
    public void swim() 
    {
        System.out.println(getName() + " (a duck) is swimming.");
    }    
}