public String buildList(Pair p, String s){
		
		if(p.getCdr().getCar() == null){
			s = s + ((Token)p.getCar()).getValue();
			return s;
		}
		else if(p.getCar() != null && p.getCdr() == null){
			s = s + ((Token)p.getCar()).getValue() + " ";
			return s;
		}
		else if(p.getCar() != null && p.getCdr() != null){
			s = s + ((Token)p.getCar()).getValue() + " ";
			return buildList(p.getCdr(), s);
		}
		else
			return s;
	}