import java.util.Arrays;

import java.util.List;

public class Person {

public String name;

public Person child;

public Person(String name) {

this.name = name;

this.child = null;

}

public static void main(String[] args) {

Person sarah = new Person("Sarah");

Person bob = new Person("Bob");

Person greg = new Person("greg");

List<Person> personList = Arrays.asList(sarah, bob, greg);

Person flatten = Person.flatten(personList);

}

public static Person flatten(List<Person> personList) {

if (personList == null || personList.size() == 0) return null;

if (personList.size() == 1) return personList.get(0);

for (int i =1; i<personList.size(); i++) {

Person curr = personList.get(i-1);

Person next = personList.get(i);

curr.child = next;

}

return personList.get(0);

}

}