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

public class Test
{
    private static IEnumerable<IList<doc>> SplitDocumentList(IEnumerable<doc> allDocuments, int maxMB)
    {
        var lists = new List<IList<doc>>();
        var list = new List<doc>();
        foreach (doc document in allDocuments)
        {
            int totalMB = list.Sum(d => d.sizemb) + document.sizemb;
            if (totalMB > maxMB)
            {
                lists.Add(list);
                list = new List<doc>();
    
            }
            list.Add(document);
        }
        if (list.Count > 0)
            lists.Add(list);
        return lists;
    }
   
	public static void Main()
	{
        var list = new List<doc>()
        {
             new doc { file = "dok1", sizemb = 5 },
             new doc { file = "dok2", sizemb = 5 },
             new doc { file = "dok3", sizemb = 5 },
             new doc { file = "dok4", sizemb = 4 },
        };

        int maxTotalFileSize = 9;

        IEnumerable<IList<doc>> splittedtDocs = SplitDocumentList(list, maxTotalFileSize);
        
      foreach(var l in splittedtDocs)
            Console.WriteLine(string.Join(",",l.Select(d=>d.file).ToArray()));
	}
    
    public class doc
    {
        public string file;
        public int sizemb;
    }
}