using System;

using System.Collections.Generic;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        string pattern = @"\d{6}[\w\d]\d";

        List<string> valid = new List<string>();

        List<string> notValid = new List<string>();

        List<string> text = new List<string>() {

            "18065900", "15074500", "16198300", "15228200", "13372700", "13012400", "16232400",

            "17041900", "17422500", "14391800", "16366400", "11111111", "16262300", "12428000",

            "13243700", "15366300", "152508A0", "14335900", "17414700", "17330200", "136542A2",

            "NotValid", "134554AO", "11I132A0"

        };

        foreach(var item in text)

        {

            Match result = Regex.Match(item, pattern);

            if (result.Success)

                valid.Add(item);

            else

                notValid.Add(item);

        }

        Console.WriteLine("Valid Entries:");

        foreach(var item in valid)

            Console.Write($"{item} ");

        Console.WriteLine(string.Empty);

        Console.WriteLine("Unvalid Entries:");

        foreach(var item in notValid)

            Console.Write($"{item} ");

    }

}