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 Go (1.6) (judge verdict: Accepted)

package main

import (
	"fmt"
	"strings"
)

func hasSerial(a []string) bool {
	for i, v := range a {
		if i == 0 {
			continue
		}
		if a[i-1] == v {
			return true
		}
	}
	return false
}

func main() {
	var s string
	fmt.Scan(&s)
	a := strings.Split(s, "")

	if hasSerial(a) {
		fmt.Println("Bad")
	} else {
		fmt.Println("Good")
	}
}