using System;

using System.Linq;

public class Program {

  public static void Main() {

    static string MyConvert(string source) => string.Join(".", source

      .Chunk(2)

      .Select(chunk => Convert.ToInt32(new string(chunk), 16)));

​

    string[] tests = {

      "6F6F6F6F",

      "FFFFFFFF",

    };

​

    string result = string.Join(Environment.NewLine, tests

      .Select(test => $"{test}(HEXADECIMAL) - {MyConvert(test)}(IPADDRESS)"));

​

    Console.Write(result);      

  }

}