ArrayManipulator

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

namespace ArrayManipulator
{
    class ArrayManipulator
    {
        static void Main(string[] args)
        {
            var numbers = Console.ReadLine().Split().Select(int.Parse).ToList();
            string command = Console.ReadLine();
            while (command != "print")
            {
                List<string> commandList = command.Split().ToList();
                if (commandList[0] == "add")
                {
                    int index = int.Parse(commandList[1]);
                    int element = int.Parse(commandList[2]);
                    numbers.Insert(index, element);
                }
                else if (commandList[0] == "addMany")
                {
                    int index = int.Parse(commandList[1]);
                    List<int> numsToAdd = new List<int>();
                    for (int i = 2; i < commandList.Count; i++)
                    {
                        numsToAdd.Add(int.Parse(commandList[i]));
                    }
                    numbers.InsertRange(index, numsToAdd);
                }
                else if (commandList[0] == "contains")
                {
                    int element = int.Parse(commandList[1]);
                    if (numbers.Contains(element))
                    {
                        Console.WriteLine(numbers.IndexOf(element));
                    }
                    else
                    {
                        Console.WriteLine("-1");
                    }
                }
                else if (commandList[0] == "remove")
                {
                    int index = int.Parse(commandList[1]);
                    numbers.RemoveAt(index);
                }
                else if (commandList[0] == "shift")
                {
                    int positions = int.Parse(commandList[1]);
                    for (int i = 0; i < positions; i++)
                    {
                        int temp = numbers[0];
                        numbers.RemoveAt(0);
                        numbers.Add(temp);
                    }
                }
                else if (commandList[0] == "sumPairs")
                {
                    numbers = SumPairs(numbers);
                }
                command = Console.ReadLine();
            }
            Console.WriteLine("[{0}]", string.Join(", ", numbers));
        }

        static List<int> SumPairs(List<int> sums)
        {
            List<int> temp = new List<int>();
            for (int s = 0; s < 1; s++)
            {
                for (int i = 0; i < sums.Count - 1; i++)
                {
                    temp.Add(sums[i] + sums[i + 1]);
                    i = i + 1;
                }
                if (sums.Count % 2 != 0)
                {
                    temp.Add(sums[sums.Count - 1]);
                }
            }
            return temp;
        }
    }
}