Chickens and rabbits are in the same cage. The number of chickens and rabbits is the same. The total number of legs of the two animals is 168. How many chickens and rabbits are there?
鸡兔同笼，鸡和兔的数量相同，两种动物的腿加起来共有168条，鸡和兔各有多少只？
<gadget id="calculator">2 + 4</gadget>
<output>6</output>

<gadget id="calculator">168 / 6</gadget>
<output>28</output>

<result>28</result>