Array Manipulator

Array Manipulator.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Array_Manipulator
{
    class Array_Manipulator
    {
        static void Main(string[] args)
        {
            List<int> numbers = Console.ReadLine()
                .Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries)
                .Select(int.Parse)
                .ToList();
            string input = "";
            while ((input = Console.ReadLine()) != "print")
            {
                string[] commands = input
                    .Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
                string command = commands[0];
                switch (command)
                {
                    case "add":
                        {
                            int index = int.Parse(commands[1]);
                            int element = int.Parse(commands[2]);
                            if (index >= 0 && index <= numbers.Count)
                                numbers.Insert(index, element);
                            break;
                        }
                    case "addMany":
                        {
                            int index = int.Parse(commands[1]);
                            int[] elements = new int[commands.Length - 2];
                            for (int i = 2; i < commands.Length; i++)
                                elements[i - 2] = int.Parse(commands[i]);
                            if (index >= 0 && index <= numbers.Count)
                                numbers.InsertRange(index, elements);
                            break;
                        }
                    case "contains":
                        {
                            int element = int.Parse(commands[1]);
                            Console.WriteLine(numbers.IndexOf(element));
                            break;
                        }
                    case "remove":
                        {
                            int index = int.Parse(commands[1]);
                            if (index >= 0 && index < numbers.Count)
                                numbers.RemoveAt(index);
                            break;
                        }
                    case "shift":
                        {
                            int positions = int.Parse(commands[1]); // shift elements n positions to the left
                            positions %= numbers.Count;             // remove full-length shifts
                            numbers = numbers
                                .Skip(positions)
                                .Concat(numbers.Take(positions))
                                .ToList();
                            break;
                        }
                    case "sumPairs":
                        {
                            List<int> sums = new List<int>();
                            for (int i = 0; i < numbers.Count; i += 2)
                            {
                                if (i + 1 < numbers.Count)
                                    sums.Add(numbers[i] + numbers[i + 1]);
                                else
                                    sums.Add(numbers[i]);
                            }
                            numbers = sums;
                            break;
                        }
                }
            }
            Console.WriteLine("[{0}]", string.Join(", ", numbers));
        }
    }
}