class Knoten
{  int inhalt;
   int stufe;
   Knoten links;
   Knoten rechts;

   Knoten (int wert)
   { this.inhalt = wert;
     this.links  = null;
     this.rechts = null;
   }
   Knoten (int wert, int st)
   { this.inhalt = wert;
     this.links  = null;
     this.rechts = null;
     this.stufe  = st;
   }
} // class Knoten