namespace PropertiesIndexersRefOut;

public class Triple
{
  private int first;
  public int First
  {
    get
    {
      return first;
    }
    set
    {
      first = value;
    }
  }

  public int Second { get; set; }

  public int Third => First + Second;
  public override string ToString()
  {
    return $"({First}, {Second}, {Third})";
  }

  #region Indexer
  public int this[string s, int position]  
  {      
    get
    {        
      int num;
      switch (s)
      {
        case "A":
          num = this.First;
          break;
        case "B":
          num = this.Second;
          break;
        case "C":
          num = this.Third;
          break;
        default:
          throw new ArgumentException("Invalid position in triple (should be A, B, or C)");
      }
      int digit = 0;
      while(num > 0 && position > 0)
      {
        digit = num % 10;
        num /= 10;
        position--;
      }
      return digit;
    }
  }
  #endregion


  #region Operator overloading
  public static Triple operator +(Triple x, Triple y)
  {    
    return new Triple
    {
      First = x.First + y.First,
      Second = x.Second + y.Second
    };
  }
  #endregion




}