#include <iostream>

int dayamount(int month){
    switch(month){
        case 2:
            return 28;
        case 4:
        case 6:
        case 9:
        case 11:
            return 30;
        default:
            return 31;
    }
}

int main(){
    int month;
    int count = 0;
    for(month = 0; month <13; ++month){
        for(int i = 1; i < (dayamount(month)+1); ++i){
            if(month == (i%10 + i/10)){ 
                count++;
            }
        }
    }
    std::cout << count << std::endl;
    return 0;
}