using System;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        var rfcList = new string[]{"NSD1310011XA", "R&ÑZ230303H19", "NECT121212JS"};

        foreach(var rfc in rfcList)

        {

            Console.WriteLine("{0} : {1}",rfc, new Regex("[a-zA-ZñÑ&]{4}[0-9]{6}[a-zA-ZñÑ0-9&]{2,3}").IsMatch(rfc));

        }

    }

}