#include <iostream>

using namespace std;
int main(){
    int maxday[12]={31,28,31,30,31,30,31,31,30,31,30,31};
    
    int ans=0;
    for(int manth=1;manth<=12;manth++){

        for(int day=1;day<=maxday[manth];day++){

            if(manth==((day/10)+(day%10))){
                ans++;
            }
        }

    }

    cout<<ans<<endl;
}