Plant trees on both sides of a 36-meter-long road, planting one tree every 2 meters, how many trees are needed in total.
在36米长的公路两旁栽树，每隔2米栽一棵，共需多少棵树．
<gadget id="calculator">36 / 2</gadget>
<output>18</output>

<gadget id="calculator">18 + 1</gadget>
<output>19</output>

<gadget id="calculator">19 * 2</gadget>
<output>38</output>

<result>38</result>