#include <iostream>
using namespace std;

int main()
{
    int N[]={31,28,31,30,31,30,31,31,30,31,30,31};
    int judge,count=0;

    for(int month = 1; month <= 12 ; month++){
        for(int day = 1; day < N[month-1]; day++){
            judge = day / 10 + day % 10;
            if(judge == month) count++;
        }
    }

    cout << count << endl;

    return 0;
}