am=2, an=3, what is the result of a2m-n?
am=2，an=3，则a2m-n的结果是多少．
<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">4 * (1/3)</gadget>
<output>4/3 = around 1.333333</output>

<result>4/3 = around 1.333333</result>