What is the perimeter of a rectangle made of 3 squares with side lengths of 1 cm?
用3个边长1厘米的正方形拼成的长方形的周长是多少厘米．
<gadget id="calculator">1 + 1 + 1</gadget>
<output>3</output>

<gadget id="calculator">3 + 1</gadget>
<output>4</output>

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

<result>8</result>