#include <iostream>
#include <stdexcept>
#include <array>
#include <tuple>

class Date {
private:
    int day, month, year;

public:
    bool IsLeap() {
        return (!(year % 4) && year % 100) || !(year % 400);
    }

    int DayByMonth() {
        std::array<int, 12> d = {31, 28 + IsLeap(), 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
        return d[month - 1];
    }

    bool Correct() {
        return day > 0 && day <= DayByMonth() &&
               month > 0 && month < 13;
    }

    Date(int day_, int month_, int year_)
            : day(day_),
              month(month_),
              year(year_) {
        if (!Correct())
            throw std::invalid_argument("Idet medved po lesu, "
                                        "vidit - tank gorit, sel v nego "
                                        "i pogib kak geroi");
    }

    int GetDay() const {
        return day;
    }

    int GetMonth() const {
        return month;
    }

    int GetYear() const {
        return year;
    }

    void Increment() {
        day++;
        if (day > DayByMonth()) {
            day = 1;
            ++month;
        }

        if (month > 12) {
            year++;
            month = 1;
        }
    }

    void Decrement() {
        day--;
        if (day < 1) {
            --month;
            if (month < 1) {
                month = 12;
                --year;
            }
            day = DayByMonth();
        }
    }

    Date &operator++() {
        Increment();
        return *this;
    }

    Date &operator--() {
        Decrement();
        return *this;
    }
};

Date operator+(Date &cur, int ds) {
    for (int i = 0; i < ds; ++i)
        cur.Increment();
    return cur;
}

Date operator-(Date &cur, int ds) {
    for (int i = 0; i < ds; ++i)
        cur.Decrement();
    return cur;
}

bool operator<(const Date &one, const Date &two) {
    int year_one = one.GetYear(),
            month_one = one.GetMonth(),
            day_one = one.GetDay(),
            year_two = two.GetYear(),
            month_two = two.GetMonth(),
            day_two = two.GetDay();
    return std::tie(year_one, month_one, day_one)
           < std::tie(year_two, month_two, day_two);
}

bool operator==(const Date &one, const Date &two) {
    int year_one = one.GetYear(),
            month_one = one.GetMonth(),
            day_one = one.GetDay(),
            year_two = two.GetYear(),
            month_two = two.GetMonth(),
            day_two = two.GetDay();
    return std::tie(year_one, month_one, day_one)
           == std::tie(year_two, month_two, day_two);
}

bool operator!=(const Date &one, const Date &two) {
    int year_one = one.GetYear(),
            month_one = one.GetMonth(),
            day_one = one.GetDay(),
            year_two = two.GetYear(),
            month_two = two.GetMonth(),
            day_two = two.GetDay();
    return !(std::tie(year_one, month_one, day_one)
             == std::tie(year_two, month_two, day_two));
}

int operator-(const Date &one, const Date &two) {
    Date tmp = one;
    int counter = 0;
    if (tmp == two) {
        return 0;
    } else if (tmp < two) {
        for (; tmp != two; ++tmp, ++counter) {}
    } else {
        for (; tmp != two; --tmp, --counter) {}
    }
    return -counter;
}

std::ostream &operator<<(std::ostream &out, const Date &d) {
    out << d.GetDay() << '.' << d.GetMonth() << '.' << d.GetYear();
    return out;
}