Chickens and rabbits are in the same cage. Count 8 heads from the top and have 22 feet. How many chickens are there?
鸡兔同笼，从上面数8个头，有22只脚，鸡有多少只．
<gadget id="calculator">2 * 8</gadget>
<output>16</output>

<gadget id="calculator">22 - 16</gadget>
<output>6</output>

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

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

<gadget id="calculator">8 - 3</gadget>
<output>5</output>

<result>5</result>