using System;

abstract class Lothar

{

    public abstract void calc(int number);

}

​

class Collatz : Lothar

{

    public override void calc(int number)

    {

        Console.Write(number + " ");

        if (number == 1){

            return;

        }

        else if (number % 2 == 0){

            calc(number / 2);

        }

        else{

            calc(3 * number + 1);

        }

    }

}

​

public class Program

{

    public static void Main(string[] args)

    {

        Console.Write("Enter a positive integer: ");

        int result = Int16.Parse(Console.ReadLine());

        Console.Write("The collatz sequence for " + result + " is ");

        Collatz numberObj = new Collatz();

        numberObj.calc(result);

    }

}