class persom
{
	private String name = "unknown";
	private int age = -1;
	public Person()
	{
		System.out.println("constructor1 is calling");
	}
	public Person(String n)
	{
		name=n;
		System.out.println("constructor2 is calling");
		System.out.println("name is"+name);
	}
	public Person(String n,int a)
	{
		name=n;
		age=a;
		System.out.println("constructor3 is calling");
		System.out.println("name and age are"+name+","+age);
	}
	public viod shout()
	{
		System.out.println("listen to me!");
	}
}

class TestPerson
{
	public static void main(String [] args)
	{
		Person p1 = new Person();
		p1.shout();
		Person p2 = new Person("Jack");
		p2.shout();
		Person p3 = new Person("Tom",18);
		p3.shout();
	}
}