约瑟夫环运作如下：1、一群人围在一起坐成环状（如：N）2、从某个编号开始报数（如：K）3、数到某个数（如：M）的时候，此人出列，下一个人重新报数4、一直循环，直到所有人出列，约瑟夫环结束-Josephus is the application of a mathematical problem: Given n individuals (with numbers 1,2,3 ... n, respectively) sitting around a round table. From the number of people reported a few k, m is the number of out of that person　his next and from one individual to start off, count to m that another person out　so the law of repeated until the round table were all out of the column.