using System;

public class A {
  private double d, e, f;

  public A(double v){
    d = e = f = v;
  }

  public double this [string str]{
   get {
     switch (str){
       case "d": {return d;}
       case "e": {return e;}
       case "f": {return f;}
       default: throw new Exception("Error");
     }
   }
   set {
     switch (str){
       case "d": {d = value; break;}
       case "e": {e = value; break;}
       case "f": {f = value; break;}
       default: throw new Exception("Error");
    }
   }
  }   

  public override string ToString(){
    return "A: " + d + ", " + e + ", " + f;
  } 

}