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 PHP (5.6.30) (judge verdict: Runtime Error)

<?php
fscanf(STDIN,"%d %d",$s);

$b=false;
for($i=0;$i<count($s);$i++){
	if(substr($s,$i,1)==$substr($s,$+1,1)){
		$b=true;
	}
}

if($b){
	echo "Bad";
}else{
	echo "Good";
}
?>