#include <bits/stdc++.h>
#include <chrono>

using namespace std;
using namespace std::chrono;
using namespace std::chrono_literals;

int main()
{
    cin.tie(0)->sync_with_stdio(0);

    int ans = 0;

    for (int i = 1; i <= 12; i++) {
        unsigned lastday_in_month { (2015y / i / last).day() };
        for (int j = 1; j <= lastday_in_month; j++) {
            int day_sum = j / 10 + j % 10;
            if (i == day_sum) {
                ans++;
            }
        }
    }

    cout << ans << endl;

    return 0;
}