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: Accepted)

<?php
$s = trim(fgets(STDIN));
$arr = str_split($s);
$ans = 'Good';
$arr = [];
for ($i = 0; $i < strlen($s); $i++) {
    $arr[] = $s[$i];
    if ($i === 0) {
        continue;
    }
    if ($arr[$i - 1] === $arr[$i]) {
        $ans = 'Bad';
        break;
    }
}
echo $ans . PHP_EOL;