The snail climbs up a 10-meter-high pillar, climbs up 5 meters from early morning to evening every day, and slides down 4 meters at night. Like this, starting from a certain morning, how many days did the snail climb to the top of the pillar?
蜗牛沿着10米高的柱子往上爬，每天清晨到傍晚向上爬5米，夜间又滑下4米．象这样从某天清晨开始，蜗牛第多少天爬到柱顶．
<gadget id="calculator">10 - 5</gadget>
<output>5</output>

<gadget id="calculator">5 - 4</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>