using System;

using System.Linq;

​

namespace IPRangeGolf

{

    public class Program

    {

        public static void Main(string[] args)

        {

            var prog = new Program();

            Console.WriteLine(prog.f("0.0.0.0", "255.255.255.255"));

            Console.WriteLine(prog.f("255.255.255.255", "0.0.0.0"));

            Console.WriteLine(prog.f("1.2.3.4", "1.2.3.4"));

            Console.WriteLine(prog.f("56.57.58.59", "60.61.62.63"));

            Console.ReadLine();

        }

​

​

        long f(string x, string y) { 

            Func<string, long> b = s => s.Split('.')

                .Select((c, i) => long.Parse(c) << (3-i) * 8)

                .Sum(); 

            return Math.Abs(b(x) - b(y)) + 1; 

        }

    }

}

​