static void Main(string[] args) { Console.WriteLine("Please, input the annual electric consumption."); string strConsumptionPerYear = Console.ReadLine(); int.TryParse(strConsumptionPerYear, out var consuptionPerYear); ITariffCalculator productA = new ProductA(); ITariffCalculator productB = new ProductB(); TariffCalculateService service = new TariffCalculateService(productA, productB); var list = service.GetList(consuptionPerYear); Console.WriteLine("------------------------------------------------------------"); Console.WriteLine("See the two products sorted by annual tariff."); int count = 0; list.ForEach(x => { count += 1; Console.WriteLine($"{count} - {x.Title}: {x.AnnualTariff} euros"); }); Console.ReadKey(); }