a=6, b=4, how much a**2-2b=
a=6，b=4时，a**2-2b=多少
<gadget id="calculator">6 ** 2</gadget>
<output>36</output>

<gadget id="calculator">2 * 4</gadget>
<output>8</output>

<gadget id="calculator">36 - 8</gadget>
<output>28</output>

<result>28</result>