using System;

class B {
  
  public static void Main(){
    A a = new A(5); 
    double d;

    a["d"] = 6; a["e"] = 7.0; a["f"] = 8.0;

    d = a["e"] + a["f"];   // corresponds to d = a.d + a.e 
                           // in case d and e had been public

    Console.WriteLine("a: {0}, d: {1}", a, d);
  }
}