Array_Manipulator(91%)

using System;
using System.Collections.Generic;
using System.Linq;

namespace Array_Manipulator
{
    class Program
    {
        static void Main(string[] args)
        {
            string input = Console.ReadLine();

            List<int> list = input
                .Split(' ')
                .Select(int.Parse)
                .ToList();

            while (input != "print")
            {
                input = Console.ReadLine();
                string[] tokens = input.Split(' ').ToArray();
                if (tokens[0] == "add")
                {
                    int index = int.Parse(tokens[1]);
                    int element = int.Parse(tokens[2]);
                    list.Insert(index, element);
                }
                else if (tokens[0] == "addMany")
                {
                    int index = int.Parse(tokens[1]);
                    List<int> nums = tokens.Skip(2).Select(int.Parse).ToList();
                    list.InsertRange(index, nums);
                }
                else if (tokens[0] == "contains")
                {
                    int existing = int.Parse(tokens[1]);
                    if (list.Contains(existing))
                    {
                        for (int i = 0; i < list.Count; i++)
                        {
                            if (existing == list[i])
                            {
                                Console.WriteLine(i);
                            }
                        }
                    }
                    else
                    {
                        Console.WriteLine(-1);
                    }
                }
                else if (tokens[0] == "remove")
                {
                    int index = int.Parse(tokens[1]);
                    list.RemoveAt(index);
                }
                else if (tokens[0] == "sumPairs")
                {
                    int sum = 0;
                    int count = 0;
                    List<int> temp = new List<int>();
                    for (int i = 0; i < list.Count; i += 2)
                    {
                        count++;
                        if (count <= list.Count / 2)
                        {
                            sum = list[i] + list[i + 1];
                            temp.Add(sum);
                        }
                        else
                        {
                            temp.Add(list[i]);
                        }
                    }
                    list.Clear();
                    for (int j = 0; j < temp.Count; j++)
                    {
                        list.Add(temp[j]);
                    }
                }
                else if (tokens[0] == "shift")
                {
                    int shift = int.Parse(tokens[1]);
                    for (int i = 0; i < shift; i++)
                    {
                        list.Add(list[0]);
                        list.Remove(list[0]);
                    }
                }
            }
            Console.WriteLine($"[{string.Join(", ", list)}]");
        }
    }
}