301 at least how much to add, there is a factor 3.
301至少要加上多少，就有因数3．
<gadget id="calculator">3 + 0 + 1</gadget>
<output>4</output>

<gadget id="calculator">4 + 2</gadget>
<output>6</output>

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

<result>2</result>