/*fp880228*/
/*fp880409*/
/*fp910327*/

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <ctype.h>

int tmp;
int year;              /* year               */
int day;               /* day                */
int horm;              /* hor monyh          */
int verm;              /* vert month         */
int month;             /* current month      */
int daysm;             /* days per month     */
int days[126];         /* remember : 0..125  */
int daycnt;            /* day counter        */
int elcnt;             /* element counter    */
int hord;              /* hor day            */
int verd;              /* vert day           */
static char weekday[7][4] = {" su",
                             " mo",
                             " tu",
                             " we",
                             " th",
                             " fr",
                             " sa"};
static char yearmon[12][22] = {"        january      ",
                               "        february     ",
                               "         march       ",
                               "         april       ",
                               "          may        ",
                               "          june       ",
                               "          july       ",
                               "         august      ",
                               "       september     ",
                               "        october      ",
                               "        november     ",
                               "        december     "};

void main(argc, argv)
int argc;
char *argv[];
{                
  fprintf(stderr, "NFeRTARI calendar\nr.880409 v.01.01\n");
  if (argc != 2 )
  {
    fprintf(stderr, "Usage: calendar year\n" );
    exit(1);
  }
/*
  tmp = stcd_i(argv[1],&year);
*/
  for(tmp=0; tmp<strlen(argv[1]); tmp++)
   if(!isdigit(argv[1][tmp]))
    break;
  year=atoi(argv[1]);

  if ( tmp == 0 || tmp > 4 || year < 0 || year >= 2400 )
  {
    fprintf(stderr, "0 <= year <= 2399\n" );
    exit(1);
  }
  fprintf(stdout, "                              %d\n",year);
  if ( year <= 1582 )
    tmp = 4+year+(year+3)/4;
  else
    tmp = 6+year+(year+3)/4-(year-1)/100+(year-1)/400;
  day = tmp%7;                   /* 1st day of year, 0 su, 1 mo, etc. */

  for (verm=0; verm<=3; verm++)
  {
    for (horm=0; horm<=2; horm++)
    {
      month = horm+3*verm;
      switch(month)
      {
        case  0: daysm=31;        /* january   */
                 break;
        case  1: daysm=28;        /* february  */
                 if (year>1582)
                 {
                   if (year%4==0)
                     daysm = 29;
                   if (year%100==0)
                     daysm = 28;
                   if (year%400==0)
                     daysm = 29;
                 }
                 else
                 {
                   if (year%4==0)
                     daysm=29;
                 }
                 break;
        case  2: daysm=31;        /* march     */
                 break;
        case  3: daysm=30;        /* may       */
                 break;
        case  4: daysm=31;        /* april     */ 
                 break;
        case  5: daysm=30;        /* june      */
                 break;
        case  6: daysm=31;        /* july      */
                  break;           
        case  7: daysm=31;        /* august    */
                 break;
        case  8: daysm=30;        /* september */
                 break;
        case  9: daysm=31;        /* october   */
                 break;
        case 10: daysm=30;        /* november  */
                 break;        
        case 11: daysm=31;        /* december  */ 
                 break;
      }
      daycnt = 0;
      for (elcnt=0; elcnt<42; elcnt++)
      {
        if (day>elcnt || daycnt>=daysm)
          days[42*horm+elcnt]=0;
        else
        {
          day++;
          day=day%7;
          if (year==1582 && month==9 && daycnt==4)
            daycnt=14;
          daycnt++;
          days[42*horm+elcnt]=daycnt;
        }
      } 
    }
    for (horm=0; horm<=2; horm++)
      fprintf(stdout, yearmon[horm+verm*3]);
    fprintf(stdout, "\n");
    for (verd=0; verd<=6; verd++)
    {
      for (horm=0; horm<=2; horm++)
      {
        fprintf(stdout, &weekday[verd][0]);
        for (hord=0; hord<=5; hord++ )
          {
            if (days[42*horm+7*hord+verd]==0)
              fprintf(stdout, "   ");
            else
              fprintf(stdout, "%3d",days[42*horm+7*hord+verd]);
          }
      }
      fprintf(stdout, "\n");
    }
    fprintf(stdout, "\n");
  }
  exit(0);
}