A rope is 18 decimeters long, and it can wrap around the table exactly twice. What is the circumference of the table in decimeters?
一条绳子长18分米，绕着桌子的四周正好可以围两圈，桌子的周长是多少分米．
<gadget id="calculator">18 / 2</gadget>
<output>9</output>

<result>9</result>