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 Solution
{
    public string Proc(string val)
    {
        char before = ' ';
        foreach (var it in val)
        {
            if (before == it) return "Bad";
            before = it;
        }

        return "Good";
    }
}

class Program
{
    static string[] GetVals(string splitChar)
    {
        var src = Console.ReadLine();
        return src.Split(new string[] { splitChar }, StringSplitOptions.None);
    }

    static string[] GetVals(char splitChar)
    {
        var src = Console.ReadLine();
        return src.Split(splitChar);
    }

    static string GetVal()
    {
        return Console.ReadLine();
    }

    static void Write(object o)
    {
        Console.WriteLine(String.Format("{0}", o));
    }

    static int ParseI(string val) { return int.Parse(val); }
    static double ParseD(string val) { return double.Parse(val); }

    static void Main(string[] args)
    {
        //var s = GetVal();
        //Write(new Solution().Proc(s));

        Write(new Solution().Proc("3776"));//B
        Write(new Solution().Proc("8080"));//G
        Write(new Solution().Proc("1333"));//B

        GetVal();
    }
}