#include<stdio.h>
int main()
{
    int month;

    int days[12]={31,28,31,30,31,30,31,30,31,30,31,30}
    scanf("%d",&month);
    if(month<1||month>12)
    {
        printf("Invaid input");
        return 0;
    }
    else {
        if(month==2)
    {
        printf("28 days(29 in leap years)");
    }
    else
    printf("%d",days[month-1]);
    }
}return 0;