A circle of the tree trunk is 2 decimeters, and a rope goes around the tree trunk twice and there is 1 decimeter more, how many decimeters is the length of this rope?
树干一圈有2分米，一根绳子绕树干2圈还多1分米，这根绳子长多少分米．
<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<result>5</result>