A triangle can be formed by three 1 cm long sticks, how many sticks are needed to form 5 such triangles
用三根1厘米长的小棒能围成一个三角形，若要围成5个这样的三角形至少需要多少根
<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">3 + 8</gadget>
<output>11</output>

<result>11</result>