#include <bits/stdc++.h>

using namespace std;

#define REP(i, n) for(int i = 0; i < n; i++)

int main() {
    int days[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

    int ans = 0;
    for (int i = 0; i < 12; ++i) {
        for (int j = 0; j < days[i]; ++j) {
            if ((j + 1) / 10 + (j + 1) % 10 == i + 1) ans++;
        }
    }

    cout << ans << endl;
    return 0;
}