using System;

using System.Threading;

public class Program

{

    public static void Main()

    {

        var rr = new RoundRobin();

        Console.WriteLine($"{rr.GetNextIndex()}");

        Console.WriteLine($"{rr.GetNextIndex()}");

        Console.WriteLine($"{rr.GetNextIndex()}");

    }

    private class RoundRobin

    {

        private uint _RoundRobin = uint.MaxValue - 1;

        public uint GetNextIndex()

        {

            var nextIndex = Interlocked.Increment(ref _RoundRobin);

            return nextIndex;

        }

    }

}