class Date {
protected:
 int year;
 int month;
 int day;

public:
 class DateErrors {};
 class OutOfRange:public DateErrors {};
 class YearOutOfRange:public OutOfRange {};
 class MonthOutOfRange:public OutOfRange {};
 class DayOutOfRange:public OutOfRange {};

public:
 Date(int year=1901, int month=1, int day=1)
   { Set(year, month, day); }

 int Year()
   { return year; }
 int Month()
   { return month; }
 int Day()
   { return day; }
 void Set(int year,int month,int day);