It takes Xiaoli 6 seconds to walk from the first floor to the second floor, so how many seconds does it take to walk to the fourth floor?
小丽从一楼走到二楼要用6秒，这样走到四楼共用多少秒．
<gadget id="calculator">2 - 1</gadget>
<output>1</output>

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

<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">6 * 3</gadget>
<output>18</output>

<result>18</result>