02. Shoot for the Win

using System;

namespace ShootForTheWin
{
    class Program
    {
        static void Main(string[] args)
        {
            var targets = Console.ReadLine().Split(' ').Select(int.Parse).ToList();
            int index, shotTargets = 0;
            string command;

            while ((command = Console.ReadLine()) != "End")
            {
                index = int.Parse(command);
                if (index >= 0 && index < targets.Count)
                {
                    for (int i = 0; i < targets.Count; i++)
                    {
                        if (targets[i] != -1 && index != i)
                        {
                            if (targets[i] > targets[index])
                            {
                                targets[i] -= targets[index];
                            }
                            else
                            {
                                targets[i] += targets[index];
                            }
                        }
                    }
                    targets[index] = -1;
                    shotTargets++;
                }
            }

            Console.WriteLine($"Shot targets: {shotTargets} -> {String.Join(' ', targets)}");
        }
    }
}