using System;

public class Test
{
	public static void Main()
	{
string wikiPageUrl = @"http://i...content-available-to-author-only...a.org/wiki/ʿAbd_Allāh_al-Sallāl";
   if (wikiPageUrl.Contains("wikipedia.org/wiki/"))
   {
      int i = wikiPageUrl.LastIndexOf("wikipedia.org/wiki/");
      Console.WriteLine(i);
   }
   }
}