using System;

using System.Globalization;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

         string text = "It is @google.com or @google";

        string result = SafeReplace(text,"@google", "some domain.", true);

        string resultNoAtrate = SafeReplace(text,"google", "some domain.", true);

        Console.WriteLine(result);

        Console.WriteLine(resultNoAtrate);

    }

    public static string SafeReplace(string input, string find, string replace, bool matchWholeWord)

    {

        string textToFind = matchWholeWord ? string.Format(@"\b{0}\b", find) : find;

        return Regex.Replace(input, textToFind, replace);

    }

}