array modifier

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


namespace Order_By_Age
{
    class Program
    {
        static void Main(string[] args)
        {
            List<int> numbers = Console.ReadLine().Split().Select(int.Parse).ToList();

            string[] command = Console.ReadLine().Split().ToArray();

            while (command[0] != "end")
            {
                if (command[0] == "swap")
                {

                    int index1 = int.Parse(command[1]);
                    int index2 = int.Parse(command[2]);

                    if ((index1 >= 0 && index1 < numbers.Count) && index2 >= 0 && index2 < numbers.Count)
                    {
                        int temp = numbers[index1];
                        numbers[index1] = numbers[index2];
                        numbers[index2] = temp;
                    }

                }
                if (command[0] == "multiply")
                {
                    int index1 = int.Parse(command[1]);
                    int index2 = int.Parse(command[2]);

                    if ((index1 >= 0 && index1 < numbers.Count) && index2 >= 0 && index2 < numbers.Count)
                    {
                        numbers[index1] *= numbers[index2];
                    }
                }
                if (command[0] == "decrease")
                {
                    for (int i = 0; i < numbers.Count; i++)
                    {
                        numbers[i] -= 1;
                    }
                }

                command = Console.ReadLine().Split().ToArray();
            }

            Console.WriteLine(string.Join(", ", numbers));
        }
    }
}