List Manipulation Basics

package com.company;


import java.lang.reflect.Array;
import java.util.*;
import java.util.stream.Collectors;

public class Main {


    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        List<Integer> numbers = Arrays.stream(sc.nextLine().split(" "))
                .map(Integer::parseInt)
                .collect(Collectors.toList());
        String command =sc.nextLine();

        while (!command.equals("end")){

            String[] num = command.split(" ");

            switch (num[0]){
                case "Add" :
                    int numberToAdd =Integer.parseInt(num[1]);
                    numbers.add(numberToAdd);
                    break;
                case "Remove" :
                    int numberToRemove = Integer.parseInt(num[1]);
                    numbers.remove(numberToRemove);
                    break;
                case "RemoveAt" :
                    int indexToRemove  = Integer.parseInt(num[1]);
                    numbers.remove(indexToRemove);
                    break;
                case "Insert" :
                    int numberToInsert = Integer.parseInt(num[1]);
                    int indexToInsert = Integer.parseInt(num[2]);
                    numbers.add(indexToInsert,numberToInsert);
                    break;
            }
            command = sc.nextLine();
        }
        System.out.println(numbers.toString()
        .replaceAll("[\\[\\],]",""));

    }
}