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;

/**
 * AtCoder Beginner Contest 131<br>
 * A - Security<br>
 * <br>
 * https://atcoder.jp/contests/abc131/tasks/abc131_a<br>
 */
public class Main {

    public static void main(String[] args) {
        try (Scanner sc = new Scanner(System.in)) {
            // 標準入力より入力を取得
            String[] input = sc.nextLine().split("");
            // 判定
            Result r = renzokuNum(input);
            // 結果出力
            System.out.println(r.toString());
        }
    }

    /**
     * 番号が連続しているかどうかの判定 
     */
    private static Result renzokuNum(String[] input) {
        for (int i = 0; i < input.length - 1; i++) {
            if (input[i].equals(input[i + 1])) {
                return Result.Bad;
            }
        }
        return Result.Good;
    }

    /**
     * 処理結果 
     */
    enum Result {
        Good("Good"), Bad("Bad"),
        ;

        private String kbn;

        private Result(String kbn) {
            this.kbn = kbn;
        }

        public String toString() {
            return this.kbn;
        }
    }
}