A well is 8 meters deep, and a snail climbs up from the bottom. It climbs up 3 meters during the day and slides down 2 meters at night. How many days does it take to reach the mouth of the well?
一口井深8米，一只蜗牛从最底下开始往上爬，白天爬上3米，夜里滑下2米，这样它多少天能爬到井口．
<gadget id="calculator">8 - 3</gadget>
<output>5</output>

<gadget id="calculator">3 - 2</gadget>
<output>1</output>

<gadget id="calculator">5 / 1</gadget>
<output>5</output>

<gadget id="calculator">5 + 1</gadget>
<output>6</output>

<result>6</result>