goldmine

number_of_locations = int(input())
for location in range(number_of_locations):
    expected_average_income = float(input())
    days_for_current_location = int(input())
    current_income = 0
    for days in range(days_for_current_location):
        daily_income = float(input())
        current_income += daily_income
    real_average_income = current_income / days_for_current_location
    if real_average_income >= expected_average_income:
        print(f"Good job! Average gold per day: {real_average_income:.2f}.")
    else:
        final_result = expected_average_income - real_average_income
        print(f"You need {final_result:.2f} gold.")