import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.IntSummaryStatistics;
import java.util.List;
import java.util.NoSuchElementException;

public class Main {
    public static void main(String[] args) {
        System.out.println("Hello World");
        final List<Person> people = generatePeople();
        // find oldest person in the list
        Person oldestPerson = people.stream()
            .max(Comparator.comparing(Person::getAge))
            .orElseThrow(NoSuchElementException::new);
        System.out.println("Oldest person is: " + oldestPerson.getName());
        // find max,min,avg age of the people
        IntSummaryStatistics stats = people.stream()
            .mapToInt(Person::getAge)
            .summaryStatistics();
        System.out.println("Max Age: " + stats.getMax());
        System.out.println("Min Age: " + stats.getMin());
        System.out.println("Avg Age: " + stats.getAverage());
    }

    public static List<Person> generatePeople() {
        return Arrays.asList(
            new Person("John", 25),
            new Person("Jane", 30),
            new Person("Jack", 20),
            new Person("Jill", 35)
        );
    }

    /**
* Capitalizes the first letter of a given string and lowercases the rest.
*
* @param s The string to capitalize
* @return The capitalized string
*/
    public static String capitalize(String s) {
        /*
This code checks if the length of the string "s" is 0. If it is, it returns the string.
If not, it returns the first character of the string in uppercase and the rest of the characters in lowercase.
*/
        if (s.length() == 0)
            return s;
        return s.substring(0, 1).toUpperCase() + s.substring(1).toLowerCase();
    }
}

// class Person with name and age
class Person {
    private String name;
    private int age;

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

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }
}