#include<stdio.h>
int main() {
    int month;
    scanf("%d",&month);
    if (month < 1 || month > 12) {
        printf("Invalid input\n");
    }
        else if(month == 2) {
            printf("Invalid input\n ");
        }
        else if(month == 4 || month ==6 || month == 9 || month ==11) {
            
            |
        printf("30 days\n");
        else {
        printf("31 days\n");
        }
    
    return 0;
}