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.Linq;

namespace B___Bite_Eating
{
    class Program
    {
        static void Main(string[] args)
        {
            var N_L = Console.ReadLine().Split().Select(int.Parse).ToArray();
            int N = N_L[0], L = N_L[1];
            int a = L, l = L + N - 1;
            bool flg = a < 0 && l > 0;

            var sum = (double)N / 2 * (a + l) - (flg ? 0 : l <= 0 ? l : a);
            Console.WriteLine(sum);
        }
    }
}