题解 | 卡拉兹函数

import java.util.*;
public class Main{
    public static void main(String[] args){
        Scanner scan = new Scanner(System.in);
        int n = scan.nextInt();
        if(n%2==0){
            System.out.println(n/2);
        }else{
            System.out.println(3*n+1);
        }
    }
}