2、　　约瑟夫（Josephus）环问题：编号为1,2,3,…,n的n个人按顺时针方向围坐一圈，每人持有一个密码（正整数）。一开始任选一个正整数作为报数的上限值m，从第一个人开始按顺时针方向自1开始顺序报数,报到m时停止。报m的人出列，将他的密码作为新的m值，从他在顺时针方向上的下一人开始重新从1报数，如此下去，直到所有人全部出列为止。- Joseph (Josephus) Central issue: numbered 1,2,3, ..., n of n individuals sitting around the circle clockwise, each holding a password (positive integer). Choose a positive integer beginning, as reported upper limit of the number of m, starting from the first person clockwise order starting from a report number, report m, stop. Who reported m out of the column, his password as the new m values in the clockwise direction from his next began to re-number from a newspaper, it goes on until everyone up all the columns