Problem:
Score : 100 points

Problem Statement

The door of Snuke's laboratory is locked with a security code.

The security code is a 4-digit number. We say the security code is hard to enter when it contains two consecutive digits that are the same.

You are given the current security code S. If S is hard to enter, print Bad; otherwise, print Good.

Constraints

S is a 4-character string consisting of digits.

Input

Input is given from Standard Input in the following format:

S

Output

If S is hard to enter, print Bad; otherwise, print Good.

Sample Input 1

3776

Sample Output 1

Bad

The second and third digits are the same, so 3776 is hard to enter.

Sample Input 2

8080

Sample Output 2

Good

There are no two consecutive digits that are the same, so 8080 is not hard to enter.

Sample Input 3

1333

Sample Output 3

Bad

Sample Input 4

0024

Sample Output 4

Bad

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

import Control.Monad
 
import Data.Ord
import Data.List
import Data.Function
import Data.Maybe
 
import qualified Data.ByteString.Char8 as BS
 
import Debug.Trace
 
tuplify2 :: [a] -> (a, a)
tuplify2 (x:y:_) = (x, y)
tuplify2 _ = undefined
 
readInt = read :: String -> Integer
readIntTuple = tuplify2 . map readInt . words
readIntList = map readInt . words
 
getInt = readInt <$> getLine
getIntList = readIntList <$> getLine
getIntMatrix = map readIntList . lines <$> getContents
getIntTuple = readIntTuple <$> getLine
getIntTuples = map readIntTuple . lines <$> getContents
 
main = do
  s <- getLine
  print $ f s

f s@(c1:c2:c3:c4:_)
  | c1 == c2 = "Bad"
  | c2 == c3 = "Bad"
  | c3 == c4 = "Bad"
  | otherwise = "Good"