06. Gold Mine

number_of_locations = int(input())

for i in range(number_of_locations):
    expected_average_yield_per_day = float(input())
    days = int(input())
    gold_collected = 0


    for day in range(days):
        gold_collected_per_day = float(input())
        gold_collected += gold_collected_per_day

    average_gold_collected_per_day = gold_collected / days

    if average_gold_collected_per_day >= expected_average_yield_per_day:
        print(f"Good job! Average gold per day: {average_gold_collected_per_day:.2f}.")
    else:
        print(f"You need {expected_average_yield_per_day - average_gold_collected_per_day:.2f} gold.")