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: Runtime Error)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

class Program {
    static void Main (string[] args) {
          

        string[] str = Console.ReadLine ().Split(' ');
        long A = long.Parse(str[0]);
        long B = long.Parse(str[1]);
        int C = int.Parse(str[2]);
        int D = int.Parse(str[3]);
        
        int tmpC = (int)(System.Math.Ceiling((double)B / C) - System.Math.Ceiling((double)(A-1) / C));
        int tmpD = (int)(System.Math.Ceiling((double)B / D) - System.Math.Ceiling((double)(A-1) / D));

        
        long E = System.Math.Abs(Lcm(C,D));
        int common =  (int)(System.Math.Ceiling((double)B/ E));

        long ans = B - A - (tmpC + tmpD - common);

        Console.WriteLine(ans);
    }
         public static long Gcd(long a, long b) {
         if (a < b)
             // 引数を入替えて自分を呼び出す
             return Gcd(b, a);
         while (b != 0) {
             var remainder = a % b;
             a = b;
             b = remainder;
         }
         return a;
     }
            public static long Lcm(long a, long b) {
            return a * b / Gcd(a, b);
        }
}