#include <iostream.h>

void print_monthname(int);
int month_length(int, int);
int is_leap_year(int);
int print_month(int, int, int);

main()
{
  int i;
  int start_on, year;

  cout << "Which year> ";
  cin >> year;
  cout << "On which day does the year begin> ";
  cin >> start_on;

  i = 1;
  while (i <= 12) {
	print_monthname(i);
	start_on = print_month(i, year, start_on);
	i++;
  }
}

void print_monthname(int m)
/*
	Displays the name of the given month m on a line by itself.

    m - month number (1 - January, ..., 12 - December)
*/
{
  if (m == 1) cout << "January" << endl;
  if (m == 2) cout << "February" << endl;
  if (m == 3) cout << "March" << endl;
  if (m == 4) cout << "April" << endl;
  if (m == 5) cout << "May" << endl;
  if (m == 6) cout << "June" << endl;
  if (m == 7) cout << "July" << endl;
  if (m == 8) cout << "August" << endl;
  if (m == 9) cout << "September" << endl;
  if (m ==10) cout << "October" << endl;
  if (m ==11) cout << "November" << endl;
  if (m ==12) cout << "December" << endl;

  return;
}

int month_length(int m, int y)
/*
   Computes the number of days in the given month.  The year is required
   to determine if February has 28 or 29 days.

   m - month we are interested in
   y - year we are interested in

   returns - the number of days in the given month
*/
{
  if (m == 1) return(31);
  if (m == 2) {
	if (is_leap_year(y))
	  return(29);
	else
	  return(28);
  }
  if (m == 3) return(31);
  if (m == 4) return(30);
  if (m == 5) return(31);
  if (m == 6) return(30);
  if (m == 7) return(31);
  if (m == 8) return(31);
  if (m == 9) return(30);
  if (m == 10) return(31);
  if (m == 11) return(30);
  if (m == 12) return(31);

  return(0);
}

int is_leap_year(int y)
/*
   Determines if the given year is a leap year.

   y - the year we are interested in

   returns - 1 if the year is a leap year
			 0 if the year is not a leap year
*/
{
  return((y % 4) == 0);
}

int print_month(int month, int year, int day)
/*
   Displays the days of the given month in the usual calendar form.

   month - the month we would like to see
   year - the year we are interested in
   day - the starting day of the month

   returns - the starting day of the next month.  If this month ends on
             day 3 then next month should start on day 4.
*/
{
  int i, max_days, cur_day;

  i = 1;
  while (i < day) {
    cout << "   ";
    i++;
  }

  cur_day = day;
  max_days = month_length(month, year);
  i = 1; 
  while (i <= max_days) {
    cout.width(3);
    cout << i;
    cur_day++;
    if (cur_day == 8) {
      cout << endl;
      cur_day = 1;
    }
	i++;
  }
  cout << endl;
  return(cur_day);
}