diff --git a/w6/Main.java b/w6/Main.java
new file mode 100644
index 0000000..be0947f
--- /dev/null
+++ b/w6/Main.java
@@ -0,0 +1,31 @@
+abstract class Animal{
+	public abstract void makeSound();
+}
+class Dog extends Animal implements Swimmable{
+	@Override
+	public void makeSound(){
+		System.out.println("woof");
+	}
+	@Override
+	public void swim(){
+		System.out.println("dog is swimming");
+	}
+}
+class Cat extends Animal{
+	public void makeSound(){
+		System.out.println("miao");
+	}
+}
+interface Swimmable{
+	void swim();
+}
+public class Main{
+	public static void main(String[] args){
+		Animal dog=new Dog();
+		Animal cat=new Cat();
+		Swimmable dog1=new Dog();
+		dog.makeSound();
+		dog1.swim();
+		cat.makeSound();
+	}
+}
\ No newline at end of file