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 PHP7 (7.0.15) (judge verdict: Runtime Error)

<?php

while ($stdin = fgets(STDIN)) {
    $line[] = trim($stdin);
}
foreach ($line as $key => $value) {
    $data[] = explode(' ', $value);
}

//foreach ($data as &$line) {
//    $line = array_map(function($val) { return (int)$val; }, $line);
//}

$S = (string)$data[0][0];
$len = mb_strlen($S);

$secure = true;
for ($i = 0;$i < $len - 1; $i++) {
   if (substr($S, $i, 1) === substr($S, $i + 1, 1)) {
        $secure = false;
   }
}

$ans = $secure ? 'Good' : 'Bad';

printf('%s', $ans);

?>