public static double GetAverage()
        {
            int count = 0, sum = 0;
            int x = int.Parse(Console.ReadLine());
            while (x != -1)
            {
                count++;
                sum = sum + x;
                x = int.Parse(Console.ReadLine());
            }
            if (count < 100)
                return 0;
            return ((double)sum / count);
        }

        public static bool GoodDay(double[] a)
        {
        for (int i = 0; i < a.Length – 1 ; i++)
            if (a[i] > 8 && a[i + 1] > 8)
              return false;
            return true;
        }

        public static void Main()
        {
        double[] arr = new double[12];
        for (int i = 0; i < arr.Length; i++)
        {
        arr[i] = GetAverage();
        }
         if (GoodDay(arr) == true)
           Console.WriteLine("Good day");
         else
           Console.WriteLine("Not good day");
     }