The perimeter of a rectangle is 10 centimeters, its width is 2 centimeters, what is its length in centimeters
一个长方形周长是10厘米，它的宽是2厘米，长是多少厘米
<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">5 - 2</gadget>
<output>3</output>

<result>3</result>