A rectangle is surrounded by a wire with a length of 16 cm. The length and width are required to be prime numbers. What is its area in square meters?
用一条长16厘米的铁丝围成一个长方形，要求长和宽都是质数，它的面积是多少平方米．
<gadget id="calculator">3 * 5</gadget>
<output>15</output>

<result>15</result>