约瑟夫环是一个数学的应用问题：已知n个人（以编号1，2，3...n分别表示）围坐在一张圆桌周围。从编号为k的人开始报数，数到m的那个人出列；他的下一个人又从1开始报数，数到m的那个人又出列；依此规律重复下去，直到圆桌周围的人全部出列。

-Josephus is the application of a mathematical problem: Given n individuals (in numbers 1,2,3 ... n, respectively) sitting around a round table around. From the number of people began to report the number of k, the number to m the man out of the column　his newspaper the next person and from a starting number, the number to the man and the m columns　so regular repeated until the round table around were all out of line.