using System;

using System.Linq;

using System.Collections.Generic;

using shortid;

using shortid.Configuration;

public class Program

{

    public static void Main()

    {

        var hash = new HashSet<string>();

        ShortId.SetCharacters("ABCDEFGHIJKLMNPQRSTUVWXYZ123456789abcdefghijklmnpqrstuvwxyz");

        var options = new GenerationOptions(length: 8, useSpecialCharacters: false);

        foreach (var idx in Enumerable.Range(1,100000))

        {

            var code = ShortId.Generate(options).ToUpper().Substring(0,6);

            hash.Add(code);

        }

        Console.WriteLine($"{hash.Count} unique codes generated");

    }

}