using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine(ReplacePath("http://localhost:61310/StringtoConvert?Id=1", "ConvertedString"));

    }

    private static string ReplacePath(string url, string newPath)

    {

        Uri uri = new Uri(url);     

        return $"{uri.GetLeftPart(UriPartial.Authority)}/{newPath}{uri.Query}";

    }

}