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 C# (Mono 4.6.2.0) (judge verdict: Wrong Answer)

using System;
class Program
{
	static void Main(string[] args)
	{
		string s = Console.ReadLine();
		string status = "good";
      	string s1 = s.Substring(0,1);
      	string s2 = s.Substring(1,1);
      	string s3 = s.Substring(2,1);
      	string s4 = s.Substring(3,1);
      	if(s1 == s2){
          status = "bad";
        }
      	if(s2 == s3){
          status = "bad";
        }
      	if(s3 == s4){
          status = "bad";
        }
		Console.WriteLine(status);
	}
}