There are 8 layers of wood in a pile, with 2 logs on the top layer and 9 logs on the bottom layer. There is a difference between two adjacent layers. How many logs are there in total?
有一堆木头，共8层，最上层2根，最下层9根，相邻两层相差一根，这堆木头共多少根？
<gadget id="calculator">2 + 9</gadget>
<output>11</output>

<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">11 * 4</gadget>
<output>44</output>

<result>44</result>