Josephus 问题的解答。n个孩子围成圆圈，选任一个数m，从第一个孩子开始数，数到m停止，这个孩子离开，再从第一个开始数，直到剩下一个孩子。-Josephus questions. n children surrounded the circle, selected a number of m, from the beginning of their first child a few, a few m to stop the child to leave, and then started from the first few, until the rest of a child.