using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var data = Enumerable.Range(0,100).ToArray();

        var mm = new List<int>();

        var maxUsers = 12;

         foreach (var idx in Chunk(data, maxUsers))

            {

                //0,1|2,3

                var emailsub = data.Skip(idx.First()).Take(idx.Last() - idx.First() + 1).ToArray();

             mm.AddRange(emailsub);

             Console.WriteLine(String.Join(",", emailsub));

         }

        Console.WriteLine("match=" + (string.Join("|",data) == string.Join("|",mm)));

    }

         internal static IEnumerable<IEnumerable<T>> Chunk<T>(IEnumerable<T> source, int chunksize)

        {

            var tl = new List<T>();

            foreach (var elem in source)

            {

                tl.Add(elem);

                if (tl.Count >= chunksize)

                {

                    yield return tl;

                    tl = new List<T>();

                }

            }

            if (tl.Count > 0) yield return tl;

        }

}