protected string render(int level=1, string indent=""){
			for(int i = 0; i < level; i++) 	indent += "\t";
			return "Person: " + vname + ((nname != "")? " Nachname: " + nname : "")+((vater != null)?"\n"+ indent +"Vater:\n"+ indent + "\t" + vater.render(level+1): "")+((mutter != null)? "\n" + indent + "Mutter:\n"+ indent + "\t" + mutter.render(level+1) + "\n": "");
		}

		public override string ToString(){
			return render();
		}