DoublyLL Java

import java.util.*;

class Main{
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        LinkedList<Integer> list = new LinkedList<>();
        boolean argument=true;
        while(argument){
            int arg;
            System.out.println("**********");
            System.out.println("Enter choice:\n1. Insertion\n2. Deletion\n3. Display\n0. Exit");
            System.out.println("**********");
            arg = in.nextInt();
            switch(arg){
                case 1://insertion
                {
                    System.out.println("Enter element to be inserted:");
                    list.add(in.nextInt());
                    break;
                }
                case 2://Deletion
                {
                    if(list.isEmpty()){
                        System.out.println("List Empty!");
                        break;
                    }
                    System.out.println("**********");
                    System.out.println("Enter choice:\n1. Delete from begining\n2. Delete from end");
                    System.out.println("3. Delete from particular position\n0. Exit");
                    System.out.println("**********");
                    int delArg= in.nextInt();
                    switch(delArg){
                        case 1://del from front
                            list.removeFirst();
                            break;
                        case 2://del from end
                            list.removeLast();
                            break;
                        case 3:
                            System.out.println("Enter the element to be deleted:");
                            int delElement = in.nextInt();
                            int flag=0;
                            int i=-1;
                            Iterator<Integer> itr = list.iterator();
                            try{
                                while(itr.hasNext()){
                                    i++;
                                    if(itr.next()==delElement){
                                        list.remove(i);
                                        flag=1;
                                    }
                                }
                            }
                            catch(ConcurrentModificationException e){
                                System.out.println("Exception occured");
                                break;
                            }

                            if(flag!=1){
                                System.out.println("Element not found!");
                            }
                            break;
                        case 0:
                            break;
                    }
                    break;
                }
                case 3://Display
                    Iterator<Integer> it = list.iterator();
                    System.out.print("[ ");
                    try{
                        while(it.hasNext()){
                            System.out.print(it.next()+" ");
                        }
                        System.out.println("]");
                    }
                    catch(ConcurrentModificationException e){
                        System.out.print("Exception occured");
                        break;
                    }
                    break;
                case 0://End
                    System.out.println("Exiting...");
                    argument=false;
                    break;
                default:
                    System.out.println("Invalid Argument!");
                    break;
            }
        }
    }
}