using System;

namespace Gold_Mine
{
    internal class Program
    {
        static void Main(string[] args)
        {
            int location = int.Parse(Console.ReadLine());
            double average = 0;

            for (int i = 0; i < location; i++)
            {
                double averageMiningPerDay = double.Parse(Console.ReadLine());
                int days = int.Parse(Console.ReadLine());

                for (int j = 0; j < days; j++)
                {
                    double mining = double.Parse(Console.ReadLine());
                    average += mining;
                }
                average /= days;

                if (average > averageMiningPerDay)
                {
                    Console.WriteLine($"Good job! Average gold per day: {average:f2}.");
                }
                else
                {
                    Console.WriteLine($"You need {averageMiningPerDay - average:f2} gold.");
                }
            }

        }
    }
}