watermelons are exchanged for 14 apples, 2 apples are exchanged for 4 oranges, how many oranges can be exchanged for one watermelon.
2个西瓜换14个苹果，2个苹果换4个桔子，一个西瓜可以换多少个桔子．
<gadget id="calculator">2 * 7</gadget>
<output>14</output>

<result>14</result>