What will be the output of the following Java program?

import java.util.*;
    class Arraylist 
    {
        public static void main(String args[]) 
        {
            ArrayList obj = new ArrayList();
            obj.add("A");
            obj.add("B");
            obj.add("C");
            obj.add(1, "D");
            System.out.println(obj);
        }
    }