The perimeter of a rectangle is 40 centimeters, its length and width in centimeters are composed of a prime number and a composite number, what is the minimum area in square centimeters.
一个长方形的周长是40厘米，它的长和宽的厘米数由一个质数与一个合数组成，最小面积是多少平方厘米．
<gadget id="calculator">2 * 18</gadget>
<output>36</output>

<result>36</result>