using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine(FilterValue("efd#dfds"));

    }

    private static string FilterValue(string input)

    {

        // If the string does not contain #, return value

        if (!input.Contains("#"))

            return input;

​

        // # does exist in the string so 

        // 1) find its location

        // 2) Read everything from that point to the end of the string

        // 3) Return the SubString value

        var index = input.IndexOf("#", StringComparison.Ordinal) + 1;

        return input.Substring(index, input.Length - index);

    }

}