HDOJ 1210 Eddy's 洗牌问题

import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while(sc.hasNext()){
            int n = sc.nextInt();
            int pos =1;
            int t = 2*n+1;
            int count=0;
            while(true){
                pos = pos*2%t;
                count++;
                if(pos == 1){
                    break;
                }
            }
            System.out.println(count);
        }
    }
}