Problem:
Score : 300 points

Problem Statement

Given an integer N, find the base -2 representation of N.

Here, S is the base -2 representation of N when the following are all satisfied:

S is a string consisting of 0 and 1.

Unless S = 0, the initial character of S is 1.

Let S = S_k S_{k-1} ... S_0, then S_0 \times (-2)^0 + S_1 \times (-2)^1 + ... + S_k \times (-2)^k = N.

It can be proved that, for any integer M, the base -2 representation of M is uniquely determined.

Constraints

Every value in input is integer.

-10^9 \leq N \leq 10^9

Input

Input is given from Standard Input in the following format:

N

Output

Print the base -2 representation of N.

Sample Input 1

-9

Sample Output 1

1011

As (-2)^0 + (-2)^1 + (-2)^3 = 1 + (-2) + (-8) = -9, 1011 is the base -2 representation of -9.

Sample Input 2

123456789

Sample Output 2

11000101011001101110100010101

Sample Input 3

0

Sample Output 3

0

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace CSharp_AtCoder
{


    class Program
    {



        static void Main(string[] args)
        {
            int N = int.Parse(Console.ReadLine());

            string minus_binary = "";
            while (N != 0)
            {
                minus_binary = Math.Abs((N % -2)).ToString() + minus_binary;
                if (N % 2 == 0 || N > 0) N /= -2;
                else if (N < 0) N = N / -2 + 1;
            }

            if (minus_binary == "") minus_binary = "0";

            Console.WriteLine(minus_binary);
        }
    }
}