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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.Scanner;

// A - Security
// https://atcoder.jp/contests/abc131/tasks/abc131_a
public class Main {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        char[] S = scanner.next().toCharArray();
        scanner.close();

        char oldC = S[0];

        for (int i = 1; i< S.length; i++) {
            if (oldC == S[i]) {
                System.out.println("Bad");
                return;
            }
            oldC = S[i];
        }

        System.out.println("Good");
    }
}