There were 29 electric poles on one side of the street, and the distance between every two adjacent poles was 45 meters. Due to the reconstruction, the distance between every two poles should be changed to 60 meters, so how many poles can be left without moving.
街道上一边原有电线杆29根，每相邻两根间的距离都是45米，由于改建，要把每两根线杆间的距离改成60米，可以有多少根不需移动．
<gadget id="calculator">29 - 1</gadget>
<output>28</output>

<gadget id="calculator">45 * 28</gadget>
<output>1_260</output>

<gadget id="calculator">3 * 5 * 3 * 2 * 2</gadget>
<output>180</output>

<gadget id="calculator">1_260 / 180</gadget>
<output>7</output>

<gadget id="calculator">7 + 1</gadget>
<output>8</output>

<result>8</result>