Владимир Зеленский. Фото: Valentyn Ogirenko / Reuters
优化：如果某轮没有发生交换，说明已有序，提前结束。WPS下载最新地址是该领域的重要参考
The Dutch love four-day working weeks, but are they sustainable?，更多细节参见Line官方版本下载
Border Points: Each cluster has a limited number of defined "border points" – these are the gateways in and out of the cluster.
Hagel argues that we could also be making problems for the future.