有n个人围成一圈，顺序排号。从第一个人开始报数（从1到3报数），凡报到3的人退出



　　　圈子，问最后留下的是原来第几号的那位。 -A circle with n individuals, in order Arranging. Number of individuals starting from the first report (report number from 1 to 3), who report to three people out of the circle, leaving the last question is who had the first few numbers.