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 Ruby (2.3.3) (judge verdict: Runtime Error)

require 'set'

class Group
  attr_accessor :x_list, :y_list
  def initialize
    @x_list = Set.new
    @y_list = Set.new
  end
end

class Pos
  attr_accessor :x, :y
  def initialize(array)
    @x = array[0]
    @y = array[1]
  end
end

def x_push(pos_list)
  pos_list.each do |pos|
    x_pos_list = @pos_hash_by_x[pos.x]
    next if x_pos_list.nil?
    @group.x_list << pos.x
    @pos_hash_by_x.delete(pos.x)
    y_push(x_pos_list)
  end
end

def y_push(pos_list)
  pos_list.each do |pos|
    y_pos_list = @pos_hash_by_y[pos.y]
    next if y_pos_list.nil?
    @group.y_list << pos.y
    @pos_hash_by_y.delete(pos.y)
    x_push(y_pos_list)
  end
end

N = gets.chop.to_i

@pos_list = []
N.times { @pos_list << Pos.new(gets.chop.split.map(&:to_i)) }
@pos_hash_by_x = @pos_list.group_by(&:x)
@pos_hash_by_y = @pos_list.group_by(&:y)

@groups = []
until @pos_hash_by_x.empty?
  key = @pos_hash_by_x.keys[0]
  x_pos_list = @pos_hash_by_x[key]
  @pos_hash_by_x.delete(key)
  @group = Group.new
  @group.x_list = [x_pos_list[0].x]
  y_push(x_pos_list)
  @groups << @group
end

puts @groups.map { |g| g.x_list.size * g.y_list.size }.inject(0, &:+) - N