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"

func main() {
	var s, prev int
	prev = -1
	for i := 0; i < 4; i++ {
		fmt.Scanf("%1d", &s)
		if prev == -1 {
			prev = s
		} else {
			if s == prev {
				fmt.Println("Bad")
				return
			}
			prev = s
		}
	}

	fmt.Println("Good")
}