using System;

public class Program

{

    public static void Main()

    {

        //

        int a=1;

        string aa=a.ToString("0000");

        //Console.WriteLine(aa);

        //Console.WriteLine((aa + "_00420_NivelacijaCena_4718_5cca34a6-7900-42e2-bcc7-62dde7f5fce6.xml").Substring(5, 5));

        string b="0001_00420_NivelacijaCena_4718_5cca34a6-7900-42e2-bcc7-62dde7f5fce6.xml";

        Console.WriteLine(b.Substring(5, 5));

    }

}