import java.util.*;


public class HelloWorld extends Mammal {

     public static void main(String []args){
        Mammal mammal = new Mammal(5);
        System.out.println(Mammal.age);
     }
}

class Mammal {

    protected static int age;

    // public Mammal() {
    //     System.out.println(this.age);
    // }

    public Mammal(int age) {
        System.out.println("I was in arg Mammal constructor");
        this.age = age;
    }

}