12 2 4 | | | ︽ | | ︾ ︵ ︽ | ︾ ︶ | | | | ︽ ︾ | | | | | | | | | 12 4 | | | | | ︽ ︾ | | | ︽ | ︾ | | ︽ ︾ | | | | | | | | | ︽ ︾ ︽ | ︾ ︽ ︾ | | | | | | | | | | ︽ ︾ | | | | | | | | | | | | | | | | |