#include <stdio.h> 
 
/*******************************\ 
30 days hath September,  
April, June and November; 
All the rest have 31, 
Excepting February alone, 
And that has 28 days clear 
And 29 in each leap year. 
\*******************************/ 
 
const int September = 9; 
const int April = 4; 
const int June = 6; 
const int November = 11; 
const int February = 2; 
 
int main() 
{ 
  int month; 
  printf("Enter number of month: "); 
  scanf("%d", &month); 
  
  if (month==September || 
      month==April || 
      month==June || 
      month==November ) 
  { 
    printf("30 days\n"); 
  } 
  else if (month==February)  
  { 
    printf("28 or 29 days\n"); 
  } 
  else  
  { 
    printf("31 days\n"); 
  } 

  return 0;
}