#include<iostream>
int main(){
    int daysOfAMonth[12]={31,28,31,30,31,30,31,31,30,31,30,31};
    int numberOfHappyDays=0;
    for(int month=1;month<=12;month++){
        int daysOfTheMonth = daysOfAMonth[month-1];
        for(int i=1;i<=daysOfTheMonth;i++)
            if((static_cast<int>(i/10)+i%10)==month){
                numberOfHappyDays++;
            }
    }
    std::cout<<numberOfHappyDays<<std::endl;
}