using System;

using System.Collections.Generic;

using System.Linq;

​

    struct Route

    {

        public int AB { get; }

        public int BC { get; }

        public int CB { get; }

        public int BA { get; }

​

        public Route(int aB, int bC, int cB, int bA)

        {

            AB = aB;

            BC = bC;

            CB = cB;

            BA = bA;

        }

​

        public bool IsLegit() =>

            AB != BA && BC != CB;

    }

​

    class Program

    {

        static void Main(string[] args)

        {

            const int drogOdADoB = 5;

            const int drogodBdoC = 4;

​

            var routes = new List<Route>();

​

            for(int i = 1; i<= drogOdADoB; i++)

                for(int j = 1; j<=drogodBdoC; j++)

                    for(int k = 1; k <= drogodBdoC; k++)

                        for(int l = 1; l <= drogOdADoB; l++)

                        {

                            var route = new Route(i, j, k, l);

                            routes.Add(route);

                        }

            var legitRoutes = routes.Where(r => r.IsLegit())

                .OrderBy(r => r.AB)

                .ThenBy(r => r.BC)

                .ThenBy(r => r.CB)

                .ThenBy(r => r.BA);

            foreach(var route in legitRoutes)

                Console.WriteLine("A-B: {0} B-C: {1}, C-B: {2}, B-A {3}", route.AB, route.BC, route.CB, route.BA);

            Console.WriteLine(legitRoutes.Count());

        }

    }