#include <stdio.h>

enum days {sunday, monday, tuesday, wednesday, thursday, 
           friday, saturday};
typedef enum days days;

days  next_day_of(days  d){
  return ( days ) (((int) d + 1) % 7);
}  

/* Return the symbolic name of day d */
char *print_name_of_day(days  d){
  char *result;
  switch (d) {
    case sunday: result = "Sunday";
       break;
    case monday: result = "Monday";
       break;
    case tuesday: result = "Tuesday";
       break;
    case wednesday: result = "Wednesday";
       break;
    case thursday: result = "Thursday";
       break;
    case friday: result = "Friday";
       break;
    case saturday: result = "Saturday";
       break;
  }
  return result;
}     

int main(void){
  
  days  day1 = saturday,  another_day;
  int i;

  printf("Day1 is %d\n", day1);

  printf("Day1 is also %s\n", print_name_of_day(day1));

  another_day = day1;
  for(i = 1; i <= 3; i++)
    another_day = next_day_of(another_day);
  
  printf("Three days after day1: %s", 
          print_name_of_day(another_day));
  printf("\n");

  return 0;
}