Chickens and rabbits are in the same cage. There are 8 heads and 26 feet. How many chickens are there?
鸡兔同笼，有8个头，26只脚，鸡有多少只．
<gadget id="calculator">8 * 4</gadget>
<output>32</output>

<gadget id="calculator">32 - 26</gadget>
<output>6</output>

<gadget id="calculator">4 - 2</gadget>
<output>2</output>

<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<result>3</result>