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 Common Lisp (SBCL 2.0.3) (judge verdict: Accepted)

(let ((s (make-array 4))
    (ans "Good"))
    (loop for i below 4 do
        (setf (aref s i) (read-char))
    )
    (if (char= (aref s 0) (aref s 1))
        (setq ans "Bad")
    )
    (if (char= (aref s 1) (aref s 2))
        (setq ans "Bad")
    )
    (if (char= (aref s 2) (aref s 3))
        (setq ans "Bad")
    )
    (princ ans)
)