Plant trees on both sides of a road, plant a tree every 5 meters, and plant 82 trees in total. How long is the road in meters?
在一条马路的两边种树，每隔5米种一棵树，共植树82棵，这条马路长多少米？
<gadget id="calculator">82 / 2</gadget>
<output>41</output>

<gadget id="calculator">41 - 1</gadget>
<output>40</output>

<gadget id="calculator">40 * 5</gadget>
<output>200</output>

<result>200</result>