using System;
using System.Linq;

public class Test
{
	class Media
	{
		public int GalleryId { get; set; }
		public string Name { get; set; }
		public int SortOrder { get; set; }
	}
	
	class Gallery
	{
		public int GalleryId { get; set; }
		public string Name { get; set; }
		public int SortOrder { get; set; }
	}
	
	public static void Main()
	{
		Gallery[] gs = new Gallery[] { new Gallery { GalleryId = 0, Name = "g0", SortOrder = 1 }, new Gallery { GalleryId = 1, Name = "g1", SortOrder = 0 } };
		Media[] ms = new Media[] { new Media { GalleryId = 0, Name = "m0", SortOrder = 1}, new Media { GalleryId = 0, Name = "m1", SortOrder = 0 }, new Media { GalleryId = 1, Name = "m2" } };
		
		    var result = ms
        .OrderBy(m => m.SortOrder)
        .GroupBy(m => m.GalleryId)
        .Join(
            gs, 
            group => group.Key,
            g => g.GalleryId,
            (group, g) => new { Gallery = g, Media = group })
        .OrderBy(x => x.Gallery.SortOrder);
            
        foreach (var x in result)
        {
        	Console.WriteLine("Gallery: " + x.Gallery.Name);
        	foreach (var m in x.Media)
        	{
        		Console.WriteLine(" Media: " + m.Name);
        	}
        }
	}
}