If there are three numbers such as 3, 4, and 12, add another number that can form a ratio. What is the maximum number of this number?
已如3、4、12三个数，再添一个能组成比例的数，这个数最大是多少．
<gadget id="calculator">12 / 3</gadget>
<output>4</output>

<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<result>16</result>