using System;

using System.Collections;

​

public class Program

{

    public static void Main()

    {

        int num = 51;

        int divisor = 2;

        ArrayList remainders = new ArrayList();

        while (num >= 1)

        {

            remainders.Add(num % divisor);

            num /= divisor;

        }

​

        remainders.Reverse();

        foreach (int v in remainders)

        {

            Console.Write(v);

        }

    }

}