import java.util.*;

public class ALRemRange extends ArrayList<Integer> {
    public static void main(String[] args){
// create an empty array list
        ALRemRange arr = new ALRemRange();
// use add() method to add values in the list
        arr.add(1);//idx:0
        arr.add(2);//idx:1
        arr.add(3);//idx:2
        arr.add(4);//idx:3
        System.out.println("The list before using removeRange:" + arr);
        try{
            //removeRange(from, to exclusive)
            //arr.removeRange(3, 4);//exclusive, only last elm: deleted (Ok)
            //arr.removeRange(3, 3);//nothing happenned: Ok
            arr.removeRange(3, 2);//why 1 copy (3), instead of error message
            //arr.removeRange(3, 1);//why 2 copies (2 & 3), no error message
            //arr.removeRange(3, 0);//why 3 copies (1, 2 & 3), no error message
        }catch(Exception e){System.out.println(e);}
        System.out.println("The list after using removeRange:" + arr);
    }
}