class FuelSystem {

    List<Double> tanks = new ArrayList<>();

    int getAverageTankFillingPercent() {
        double sum = 0;
        for (double tankFilling : tanks) { 
            sum += tankFilling;
        }
        double averageFuel = sum / tanks.size();
        // 정수 백분율로 반올림
        return Math.toIntExact(Math.round(averageFuel * 100));
    }
}