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 a mathematical application problems: Given n individuals (with numbers 1,2,3 ... n, respectively) were sitting at a round table. From the number of people reported the number k, the number to the person out of the column m　him the next person and from one reported the number of numbers to m the man was out of the line　so the law repeated until the round table were all out of the column.