# include <stdio.h>
# include <stdbool.h>

int main ( )
{
  int d;
  bool last_day;
  bool last_month;
  bool leap_year;
  int m;
  int y;

  printf ( "Enter date as m/d/y: " );
//
//  Notice that I include the slashes in the input format!
//
  scanf ( "%i/%i/%i", &m, &d, &y );
//
//  Use boolean variables to remember the answers to these questions:
//    Is this a leap year?
//    Is this the last month of the year?
//    Is this the last day of the month?
//
  leap_year = ( y % 400 == 0 ) || ( y % 4 == 0 && y % 100 != 0 );
  if ( leap_year )
  {
    printf ( "This is a leap year!\n" );
  }
  last_month = ( m == 12 );
  if ( last_month )
  {
    printf ( "This is the last month of the year!\n" );
  }

  last_day = false;

  if ( d == 28 && m == 2 && !leap_year )
  {
    last_day = true;
  }
  else if ( d == 29 && m == 2 && leap_year )
  {
    last_day = true;
  }
  else if ( d == 30 && ( m == 4 || m == 6 || m == 9 || m == 11 ) )
  {
    last_day = true;
  }
  else if ( d == 31 && ( m == 1 || m == 3 || m == 5 || m == 7 || m == 8 || m == 10 || m == 12 ) )
  {
    last_day = true;
  }
  if ( last_day )
  {
    printf ( "This is the last day of this month!\n" );
  }
//
//  Collecting the information was hard.
//  But now the computation is easy.
//
  if ( last_month && last_day )
  {
    y = y + 1;
    m = 1;
    d = 1;
  }
  else if ( last_day )
  {
    m = m + 1;
    d = 1;
  }
  else
  {
    d = d + 1;
  }

  printf ( "Next day is %i/%i/%i\n", m, d, y );


  return 0;
}