#include <stdio.h>


//////////////////////////////////////////////////////////////
int main( void )                                            //
{

    int a;

    printf("input number of month: ");  scanf("%i", &a);

    if(a == 1 || a ==  3 ||
       a == 5 || a ==  7 ||
       a == 8 || a == 10 || a == 12) { printf(   "31 days\n"); return 0; }
    if(a == 2)                       { printf("28/29 days\n"); return 0; }

    if(a  < 1 || a > 12)             { printf(   "Mistake\n"); return 0; }

                                       printf(   "30 days\n"); return 0;
}