import java.util.*;

class Child extends AncTree {
  String name;
  int yob;         // year-of-birth
  String eye;      // eye-color, e.g. "brown"
  AncTree ma, pa;  // mother, father

  /** standard constructor */
  public Child( String _name, int _yob, String _eye, AncTree _ma, AncTree _pa ) {
    // if (_ma == null) throw new NullPointerException(...);
    this.name = _name;
    this.yob  = _yob;
    this.eye  = _eye;
    this.ma   = _ma;
    this.pa   = _pa;
    }

  int size( /* Child this */ ) {
      return 1 + this.ma.size() + this.pa.size();
    }
      
  java.util.List<String> allNames( /* Child this */ ) {
      List<String> theResult = new ArrayList<String>();
      theResult.addAll( this.ma.allNames() );
      theResult.add( this.name );
      theResult.addAll( this.pa.allNames() );
      return Collections.unmodifiableList(theResult);
    }
    
    
    
    
    
    
  /** @Override */
  public String toString( /* Child this */ ) {
    return "new Child"
         + "( " + this.name.toString()
         + ", " + this.yob
         + ", " + this.eye.toString()
         + ", " + this.ma.toString()
         + ", " + this.pa.toString()
         + " )";
    }


  }