There are a bunch of utility poles, which are approximately triangular in cross-section. There are 33 poles at the bottom, and the difference between two adjacent floors is 2. How many poles are there in this pile?
有一堆电线杆，从它的截面看是一个近似的三角形，最底层有33根，相邻两层相差2根．这堆电线杆共有多少根？
<gadget id="calculator">1 + 33</gadget>
<output>34</output>

<gadget id="calculator">33 - 1</gadget>
<output>32</output>

<gadget id="calculator">32 / 2</gadget>
<output>16</output>

<gadget id="calculator">16 + 1</gadget>
<output>17</output>

<gadget id="calculator">17 / 2</gadget>
<output>17/2 = around 8.5</output>

<gadget id="calculator">34 * (17/2)</gadget>
<output>289</output>

<result>289</result>