import java.io.*;

class Date {

  private int day;    // day of month
  private int month;  // month (1..12)
  private int year;   // year (4 digits)


  // constructors
  public Date () {

    day = 1;
    month = 1;
    year = 1;
  }

  public Date (int day, int month, int year) {

    this.day = day;
    this.month = month;
    this. year = year;
  }


  // compares this date to date and returns true if they're equal
  public boolean equals (Date date) {

    if (day == date.day && month == date.month && year == date.year)

      return true;

    else

      return false;
  }


  // compares this date to date and returns true if this date is less
  //   (occurs before) date
  public boolean lessThan (Date date) {

    if (year < date.year) 

      return true;

    else if (year == date.year) {

      if (month < date.month)

        return true;

      else if (month == date.month)

        if (day < date.day)

          return true;
    }

    return false;
  }


  // formats a date into a "month day, year" format (e.g. March 2, 2000
  public String format () {

    return monthStr () + " " + day + ", " + year;
  }


  // returns true if year is a leap year
  private boolean leapYear () {

    boolean result = false;

    if (year % 400 == 0)

      result = true;

    else if (year % 100 == 0)

      result = false;

    else if (year % 4 == 0)

      result = true;

    else

      result = false;

    return result;
  }


  // increments the current date by one day
  public void nextDay () {

    boolean isLeap;

    day += 1;

    isLeap = leapYear ();

    // month rollover
    if (day > monthLength (month, isLeap)) {

      day = 1;
      month += 1;
    }

    // year rollover
    if (month > 12) {

      month = 1;
      year +=1;
    }
  }


  // returns the number of days in month
  private int monthLength (int month, boolean leap) {

    int result;

    if (month == 9 || month == 4 || month == 6 || month == 11) {

      result = 30;
    }

    else if (month == 2) {

      if (leap)

        result = 29;

      else 

        result = 28;
    }

    else

      result = 31;

    return result;
  }


  // returns string name corresponding to month number
  private String monthStr () {

    switch (month) {

      case (1)  : return "January";
      case (2)  : return "February";
      case (3)  : return "March";
      case (4)  : return "April";
      case (5)  : return "May";
      case (6)  : return "June";
      case (7)  : return "July";
      case (8)  : return "August";
      case (9)  : return "September";
      case (10) : return "October";
      case (11) : return "November";
      case (12) : return "December";
    }

    return "unknown";
  }

}