There are 35 chickens and rabbits in a cage and 94 legs. How many chickens are there?
有一个笼子里有鸡兔共35只，有脚94只，问鸡有多少只．
<gadget id="calculator">35 * 4</gadget>
<output>140</output>

<gadget id="calculator">140 - 94</gadget>
<output>46</output>

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

<gadget id="calculator">46 / 2</gadget>
<output>23</output>

<result>23</result>