using System;

//using System.Text;

string input = "http://m.imdb.com/title/tt0468569/?ref_=m_ttwo_tt";

string sub = input.ToLower().Replace("http://","").Replace("https://","");

string sub2 = sub.Substring(0,sub.IndexOf("/"));

Console.WriteLine(sub);

Console.WriteLine(sub2);

​