If 2☆3=2*3-2-3, then 9☆4=how much.
如果2☆3=2*3-2-3，那么9☆4=多少．
<gadget id="calculator">9 * 4</gadget>
<output>36</output>

<gadget id="calculator">36 - 9 - 4</gadget>
<output>23</output>

<result>23</result>