import java.util.Arrays;
import java.util.List;


interface CalculationInt {
	public int calculate(List<Person> persons);
}

interface CalculationDouble {
	public double calculate(List<Person> persons);
}

class Person {
	private String name;
	private int age;
	
	public String getName() { return name; }
	public int getAge() {return age;}
	
	Person(String name, int age) {
		this.name=name; this.age=age;
	}
}

public class Main {

	public static void main(String []args) {
		List<Person> personList = Arrays.asList(
				new Person[]{
					new Person("Oliver", 27),
					new Person("James", 23),
					new Person("Jack", 17),
					new Person("John", 27),
					new Person("Harry", 16),
					new Person("Robert", 18),
					new Person("Jacob", 38),
					new Person("Micheal", 42),
					new Person("Frank", 19),
					new Person("Charlie", 11),
				});
		
		Statistic s = new Statistic(); 
		
		System.out.println("Result: "+s.calculate(personList));
	}
		
}