class Date1
{
 protected int days;

 public Date1(int day,int month,int year) throws DateException
 {
  if(month<1||month>12||day<1)
     throw new DateException(toString());
  else if((month==4||month==6||month==9||month==11)&&day>30)
     throw new DateException(toString());
  else if(month==2)
     {
      if(year%4==0)
         {
          if(day>29)
             throw new DateException(toString());
         }
      else if(day>28)
         throw new DateException(toString());
     }
  else if(day>31)
      throw new DateException(toString());
  days=(year-1900)*365+(year-1901)/4;
  days+=day;
  if(month>=2)
     {
     days+=31;
     if(month>=3)
        {
         if(year%4==0&&year!=1900)
            days+=29;
         else
            days+=28;
         switch(month)
            {
             case 3: break;
             case 4: days+=31; break;
             case 5: days+=61; break;
             case 6: days+=92; break;
             case 7: days+=122; break;
             case 8: days+=153; break;
             case 9: days+=184; break;
             case 10: days+=214; break;
             case 11: days+=245; break;
             case 12: days+=275;
            }
        }
     }
 }

 public String toString()
 {
  int year=days/365;
  int day=days%365;
  int month;
  if(year!=0)
     day-=(year-1)/4;
  if(day<=0)
     {
      if((year-1)%4==0)
         day+=366;
      else
         day+=365;
      year--;
     }
  if(day<=31)
     month=1;
  else if(day<=59)
     {
      month=2;
      day-=31;
     }
  else if(year%4==0&&day==60&&year!=0)
     {
      month=2;
      day=29;
     }
  else
     {
      if(year%4==0&&year!=0)
         day-=60;
      else
         day-=59;
      if(day<=31)
         month=3;
      else if(day<=61)
         {
          month=4;
          day-=31;
         }
      else if(day<=92)
         {
          month=5;
          day-=61;
         }
      else if(day<=122)
         {
          month=6;
          day-=92;
         }
      else if(day<=153)
         {
          month=7;
          day-=122;
         }
      else if(day<=184)
         {
          month=8;
          day-=153;
         }
      else if(day<=214)
         {
          month=9;
          day-=184;
         }
      else if(day<=245)
         {
          month=10;
          day-=214;
         }
      else if(day<=275)
         {
          month=11;
          day-=245;
         }
      else
         {
          month=12;
          day-=275;
         }
     }
  year+=1900;
  return day+"/"+month+"/"+year;
 }

 public boolean lessThan(Date1 d)
 {
  return (days<d.days);
 }

}