using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        var deal = GetDeal<ConcreateDeal,ConcreateDealInfo>();

    }

    public static TDeal GetDeal<TDeal, TDealInfo>()

        where TDeal : DealBase<TDeal, TDealInfo>

        where TDealInfo : DealInfoBase<TDeal, TDealInfo>

    {

            return new ConcreateDeal();

    }

    public class DealBase<TDeal, TDealInfo> 

        where TDeal : DealBase<TDeal, TDealInfo>

        where TDealInfo : DealInfoBase<TDeal, TDealInfo>

    {

        public TDealInfo DealInfo {get; set;} 

    }

    public class ConcreateDeal : DealBase<ConcreateDeal, ConcreateDealInfo> {}

    public class DealInfoBase<TDeal, TDealInfo>

        where TDeal : DealBase<TDeal, TDealInfo>

        where TDealInfo : DealInfoBase<TDeal, TDealInfo>

    {

        public TDeal Deal {get; set;} 

    }

    public class ConcreateDealInfo : DealInfoBase<ConcreateDeal, ConcreateDealInfo> { } 

}