#include<iostream>
using namespace std;
class date
{
	int day;
	int month;
	int year;
public:
	date()
	{
		cout << "enter the day" << endl;
		cin >> day;
		cout << "enter the month" << endl;
		cin >> month;
		cout << "enter the year" << endl;
		cin >> year;
	}
	date(int a, int b, int c) : day(a), month(b), year(c)
	{

	}
	date(const date &prod)
	{
		this->day = prod.day, this->month = prod.month, this->year = prod.year;
	}

	date & operator+=( int d);
	date & operator-=( int d);
	date & operator =(const date&);
	int countdays();
	date & operator+=(  date&);
	date & operator -=(date&);
	friend ostream& operator<<(ostream& os,  date&);
	friend istream& operator >> (istream& is, date& prod);
	~date() {  }

};
date & date :: operator = (const date &prod1)
{
	this->day = prod1.day, this->month =prod1.month, this->year = prod1.year;
	return *this;
}

int main()
{
	date prod, prod1;
	prod = prod1;
	cout <<"prod = "<< prod;
	cout << endl;
	cout <<  "prod1 = "<<prod1;
	cout << "enter the amount of days you want to add" << endl;
	int amount; cin >> amount;
	prod += amount;
	cout <<"prod  +"<<amount<<" days =" << prod;
	prod -= amount;
	cout << "prod  -" << amount << " days =" << prod;
	prod += prod1;
	cout << "prod += prod1=" <<prod;
	prod -= prod1;
	cout <<"prod -= prod1 = "<< prod;
	system("pause");
	return 0;
}
date & date :: operator+=( date& prod1)
{
	int k = prod1.countdays();
	*this += k;
	return *this;
}
 ostream& operator<<(ostream& os,  date& prod)
{
	 os << prod.day << "." << prod.month << "." << prod.year << endl;
	 return os;
}
 istream & operator >> (istream & is, date&prod)
 {
	cout << "Ente day,month,year " << endl;
	is >> prod.day;
	 is >> prod.month;
	 is >> prod.year;
	return is ;
 }
 date & date :: operator-=(int d)
 {
	 int c = day, count = 0;
	 day -= d;
	 int i = 0;
	 if (year % 4 == 0 && (((year % 100 != 0 || year % 400 == 0)))&& month>2)i++;
	 while (d > 0)
	 {

		 if (count != 0)
		 {
			 c = day; day -= d;
		 }
		 count++;
		 switch (month-1)
		 {
		 case 0:
		 case 1:
		 case 3:
		 case 5:
		 case 7:
		 case 8:
		 case 10:
		 case 12:
		 {
			 if (day < 1)
			 {
				 d -=  c;
				 day = 31;
				 month -= 1;
				 if (month < 1)
				 {
					 month = 12;
					 year -= 1;
					 if (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0))i++;
					 if (year == 0) { cout << "Even Jesus Christ was born later..." << endl; d = 0; break; }
				 }
			 }
			 else 		d = 0;
			 break;
		 }
		 case 4:
		 case 6:
		 case 9:
		 case 11:
		 {
			 if (day < 1)
			 {
				 d -= c;
				 day = 30;
				 month -= 1;
			 }
			 else d = 0;
			 break;
		 }
		 case 2:
		 {
			 if (day < 1)
			 {
				 d -= c;
				 day = 28+i;
				 month -= 1;
				if(i==1) i = 0;
			 }
			 else 	d = 0;
			 break;
		 }

		 }
	 }
	 return *this;
 }
 date& date ::  operator+=(int d)
 {
	 int c = day, count = 0;
	 day += d;
	 int i = 0;
	 if (((year % 4 == 0 && (year % 100 != 0 || year % 400 == 0))) && month <= 2)i++;
	 while (d > 0)
	 {
		 if (count != 0) {
			 c = day; day += d;
		 }
		 count++;
		 switch (month)
		 {
		 case 1:
		 case 3:
		 case 5:
		 case 7:
		 case 8:
		 case 10:
		 case 12:
		 {
			 if (day > 31)
			 {
				 d -= 32 - c;
				 day = 1;
				 month += 1;
				 if (month > 12)
				 {
					 month = 1;
					 year += 1;
						 if (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0))i++;
				 }
			 }
			 else 		d = 0;
			 break;
		 }
		 case 4:
		 case 6:
		 case 9:
		 case 11:
		 {
			 if (day > 30)
			 {
				 d -= 31 - c;
				 day = 1;
				 month += 1;
			 }
			 else d = 0;
			 break;
		 }
		 case 2:
		 {
			 if (day > 28 + i)
			 {
				 d -= 29 + i - c;
				 day = 1;
				 month += 1;
				if(i==1) i = 0;
			 }
			 else 	d = 0;
			 break;
		 }

		 }
	 }
	 return *this;
 }
 int date :: countdays()
 {
	 int s = 0; int i = 0; if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0)i++;
	 switch (month)
	 {
	 case 1: s = 0; break;
	 case 2: s = 31; break;
	 case 3: s = 59 + i; break;
	 case 4: s = 90; break;
	 case 5: s = 120; break;
	 case 6: s = 151; break;
	 case 7: s = 181; break;
	 case 8: s = 212; break;
	 case 9: s = 243; break;
	 case 10: s = 273; break;
	 case 11: s = 304; break;
	 case 12: s = 334; break;
	 default: return 1;
	 }
	 s = s + day + (365.25 *year) - i;
	 return s;
 }
 date & date::operator -=(date&prod)
 {
	 int p = prod.countdays();
	 int t = this->countdays();
	 if (t < p)
		 cout << "Even Jesus Christ was born later..." << endl;
	 else *this -= p;
	 return *this;

 }