using System;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        var HeaderNamesWbs = new List<string>{"WBS_NUMBER", "BOE_TITLE", "SOW_DESCRIPTION", "HARRIS_WIN_THEME", "COST_BOGEY"};

        var index = HeaderNamesWbs.IndexOf("");

        Console.WriteLine(index);

    }

}