Plant trees on both sides of a road that is 10 kilometers long, and plant trees every 5 meters. Both ends of the road must be planted. How many trees should be planted in total?
在一条长10千米的路两边种树，每隔5米种一棵，路的两头都要种，一共要种多少棵．
<gadget id="calculator">1_000 / 5</gadget>
<output>200</output>

<gadget id="calculator">10 * 200</gadget>
<output>2_000</output>

<gadget id="calculator">2_000 + 1</gadget>
<output>2_001</output>

<gadget id="calculator">2_001 * 2</gadget>
<output>4_002</output>

<result>4_002</result>