using System;

public class Test
{

    class R { }
    class A : R { }
    class B : R { }

    static void pituh(A x, R y){
        Console.WriteLine("A R");
    }

    static void pituh(R x, B y){
        Console.WriteLine("R B");
    }
    
   static void pituh(R x, R y){
        Console.WriteLine("R R");
    }
    
    


    static void d(R x, R y)
    {
        dynamic a = x;
        dynamic b = y;
        pituh(a, b);
    }

    public static void Main(string[] args)
    {
    	d(new A(),new R());
    	d(new A(),new B());
	d(new A(),new B());
	d(new B(),new A());
	
    }	
}