C++ :

#include <iostream>
using namespace std;
class Date{
 public:
	Date(int y,int m,int d);
	Date();
	void show();
	void init();
private:
	int year;
	int month;
	int day; 
}; 
Date::Date(int y,int m,int d){
	year=y;
	month=m;
	day=d;
}
Date::Date(){
	int y=1900;
	int m=1;
	int d=1;
	year=y;
	month=m;
	day=d;
}
void Date::show(){
	cout<<year<<"-"<<month<<"-"<<day<<endl;
}
void Date::init(){
	cin>>year>>month>>day;
}
int main(){
	Date d1,d;
	Date d2(2100,12,12);
    d.init();
    d1.show();
    d2.show();
    d.show();
 return 0;
}