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 Perl (v5.18.2) (judge verdict: Accepted)

use strict;
use warnings;
use utf8;

my @s = split(//, <>);
my $tmp = "a";
my $i;

if ($#s != 4) {
        print "Bad";
        exit 0;
}

for ($i=0; $i<4; $i++) {
        if ($tmp eq $s[$i]) {
                print "Bad";
                exit 0;
        }
        $tmp = $s[$i];
}
print "Good";