using System;

using System.Linq;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        foreach (var i in GetKeywords())

            Console.WriteLine(i);

    }

    static List<string> GetKeywords()

    {

        var keys1 = "de at ch com net org info eu co biz me".Split(',');

        var keys2 = "".Split(',');

        var keys3 = "".Split(',');

        return (from a in keys1

                from b in keys2

                from c in keys3

                select a + b + c).ToList();

    }

}