import java.util.*;
class Human implements Comparable<Human>
{
	public int age = 0;
	public String name = "";

	public Human(String name, int age)
	{
		this.age = age;
		this.name = name;
	}

	public int compareTo(Human h)
	{
		/*
		if(this.age < h.age)
			return -1;
		else if(this.age == h.age)
			return 0;
		else
			return 1;
		*/
		return this.name.compareTo(h.name) * -1;
	}


        public static void main(String[]args)
        {
		List<Human> classList = new ArrayList<Human> ();
		classList.add(new Human("Max", 20));
		classList.add(new Human("David", 18));
		classList.add(new Human("Pete", 17));
		classList.add(new Human("Hugo", 172));
		
		printList(classList);

		System.out.println("After sorting by age");
		Collections.sort(classList);

		printList(classList);
        }

	public String toString()
	{
		return name + " " + age;
	}

	public static void printList(List<Human> classList)
	{
		for(int i = 0; i < classList.size(); i++)
		{
			System.out.println(classList.get(i));
		}
	}
 
}