蜗牛沿着8米高的柱子往上爬，每天从清晨到傍晚向上爬4米，晚间又滑下3米。像这样从某天清晨开始，第几天可以爬到柱顶？'?0x7F0S;\'\2S3a1g'A4O7l
算式：提示'q5?3{(P1u'?0x7F0S;\'\2S3a1g'A4O7l
答：第,h/Z9i5K3A'_1q6a5O.Z/m8e)v+[6N天可以爬到柱顶。'?0x7F0S;\'\2S3a1g'A4O7l