public static void countLeft2(ArrayList<Integer> list, TreeNode node, String s){
    	if(node == null	)  return;
    	
    	StringBuilder sb = new StringBuilder();
    	sb.append(s);
    	while(node != null){
    		sb.append(String.valueOf(node.val));
    		if(node.right == null && node.left == null){
    			list.add(Integer.parseInt(sb.toString()));
    		}
    		if(node.right != null){
    			countRight2(list, node.right, sb.toString());
    		}
			node = node.left;
    	}
    	
    }