The average age of Dongdong and Mingming is 14, and the average age of Mingming and Liangliang is 17. How old is Liangliang older than Dongdong?
东东、明明两个人的平均年龄是14岁，明明、亮亮两个人的平均年龄是17岁，那么亮亮比东东大几岁？
<gadget id="calculator">17 * 2</gadget>
<output>34</output>

<gadget id="calculator">14 * 2</gadget>
<output>28</output>

<gadget id="calculator">34 - 28</gadget>
<output>6</output>

<result>6</result>