public static void main(String[] args) {
        int count = 0;
        int dow = 0;
        for (int year = 1900; year <= 2000; year++) {
            for (int month = 1; month <= 12; month++) {
                for (int day = 1; day <= days(month, year); day++) {
                    dow++;

                    if (dow % 7 == 0) {
                        if (year >= 1901 && year <= 2000 && day == 1) {
                            count++;
                        }

                        dow = 0;
                    }
                }
            }
        }

        System.out.println(count);
    }