; fire privilege test
// ⚠️ 易错点3：此处返回n而非0（完全有序无需排序，长度为0），这一点在旺商聊官方下载中也有详细论述
Currently the UK experiences about seven days a year where rainfall is more than 80mm a day – considered a heavy rainfall event. If 30mm of this falls in an hour it typically triggers a flash flooding warning.。夫子对此有专业解读
Hebrew Paseq: a non-obvious finding