A snail crawls from the corner of the wall to the top of the 10-meter-high wall. It climbs up 4 meters during the day and slides down 3 meters at night. How many days does it take for the snail to climb to the top of the wall?
一只蜗牛从墙角沿墙壁向10米高的墙头爬去，白天向上爬4米，夜里往下滑3米，这只蜗牛多少天才能爬到墙头．
<gadget id="calculator">10 - 4</gadget>
<output>6</output>

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

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

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

<result>7</result>