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: Wrong Answer)

//error_reporting(0);
$N = trim(fgets(STDIN));
//list($N,$K) =  explode(" ",trim(fgets(STDIN)));
//$a =  explode(" ",trim(fgets(STDIN)));

$len = strlen($N);

for($i=1;$i<$len;$i++) {
  if ($N[$i-1]==$N[$i]) {
    printf("Bad\n");
    exit;
  }
}
printf("Good\n");