A windmill is built on a 5,400-meter-long embankment in a certain place, and one windmill is built every 45 meters from the starting point to the end point. After technical improvement, only one windmill needs to be built every 60 meters. How many windmills should there be without moving?
某地在长5400米的河堤上建风力发电风车，从起点到终点每45米建一座风车，后经技术改进，只须每60米建一座风车，这样不必移动的风车应有多少座．
<gadget id="calculator">2 * 2 * 3 * 3 * 5</gadget>
<output>180</output>

<gadget id="calculator">5_400 / 180</gadget>
<output>30</output>

<gadget id="calculator">30 + 1</gadget>
<output>31</output>

<result>31</result>