snail climbs up from the bottom of a cup with a height of 9 cm. It takes 4 minutes for each 3 cm to climb, and then rests for 2 minutes. How long does it take for the snail to climb from the bottom of the cup to the mouth of the cup?
一只蜗牛从9厘米高的杯子底往上爬，它每爬3厘米要用4分钟，然后休息2分钟，这只蜗牛从杯子底爬到杯口要用多长时间？
<gadget id="calculator">9 / 3</gadget>
<output>3</output>

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

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

<gadget id="calculator">18 - 2</gadget>
<output>16</output>

<result>16</result>