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 Haskell (GHC 7.10.3) (judge verdict: Wrong Answer)

{-# LANGUAGE BangPatterns #-}
import Control.Monad
import Data.List
import Data.Maybe
import Data.Bits

query :: Int -> String
query 0 = "0"
query i = loop i 1 []
  where
    loop 0 !sgn_ acc = acc
    loop i sgn !acc | even i = loop (i `shiftR` 1) (-sgn) $ '0':acc
                    | otherwise = loop (i' `shiftR` 1) (-sgn) $ '1':acc
      where i' = i-sgn

main :: IO ()
main = do
  n <- read <$> getLine
  putStrLn $ show $ query n