/* Date.java */

import java.io.*;

class Date {

  /* Put your private data fields here. */
  int month;
  int day;
  int year;
  String m, d, y, s;

  /** Constructs a date with the given month, day and year.   If the date is
   *  not valid, the entire program will halt with an error message.
   *  @param month is a month, numbered in the range 1...12.
   *  @param day is between 1 and the number of days in the given month.
   *  @param year is the year in question, with no digits omitted.
   */
  public Date(int month, int day, int year) {
	if( year >= 1 && year <= 9999 )
	{
		if( month >= 1 && month <= 12 )
		{
			switch(month)
				case 4:
				case 6:
				case 9:
				case 11: if( day >= 1 && day <= 30 )
						return day;
				case 2: if( day >= 1 && day <= 28 )
						return day;
				default: if( day >= 1 && day <= 31 )
						return day;
		}

		if( month == 2 && month%4 == 0 )
		{
			if( day >=1 && day <= 29 )
				return day;
		}
	}

	else
	{
		System.exit(0);
	}

	m = Integer.toString(month);
	d = Integer.toString(day);
	y = Integer.toString(year);

  }

  /** Constructs a Date object corresponding to the given string.
   *  @param s should be a string of the form "month/day/year" where month must
   *  be one or two digits, day must be one or two digits, and year must be
   *  between 1 and 4 digits.  If s does not match these requirements or is not
   *  a valid date, the program halts with an error message.
   */
  public Date(String s) {

	System.out.println( m + "/" + d + "/" + y );