Fill in the number according to the regulations: 2, 6, 12, 20, 30, how much.
按规定填数：2，6，12，20，30，多少．
<gadget id="calculator">1 * 2 * 3</gadget>
<output>6</output>

<gadget id="calculator">6 + 1</gadget>
<output>7</output>

<gadget id="calculator">1 * 2 * 3 * 7</gadget>
<output>42</output>

<result>42</result>