The length and width of a rectangle are both prime numbers, and the perimeter is 36 cm. What is the largest square centimeter of its area?
一长方形长和宽都是质数，并且周长是36cm，请问它的面积最大是多少平方厘米？
<gadget id="calculator">7 * 11</gadget>
<output>77</output>

<result>77</result>