using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Globalization;
using System.Text.RegularExpressions;
using System.IO;
using System.Diagnostics;
using System.Net.Mail;
using System.Web;
 
namespace Enum
{
    class Program
    {
        static void Main(string[] args)
        {
            string s = "http://m...content-available-to-author-only...e.com/articles/%d8%a7%d8%af%d9%85%d9%8a%d9%84%d8%b3%d9%88%d9_sto3955603/description.html";
            Console.WriteLine(s.Substring(s.IndexOf('%'), s.IndexOf('_' ) - s.IndexOf('%') + 1));
        }
    }
}
 

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