using System;

public class Program

{

    public static void Info(string str)

    {

        Console.WriteLine("string");

    }

​

    public static void InfoCvls(FormattableString str)

    {

        Console.WriteLine("Formattable");

    }

    public static void Main()

    {

        String world = "world";

        Info("Hello");

        Info($"Hello {world}");

        Info($"Hello {world}");     

    }

}