#include <bits/stdc++.h>

using namespace std;

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

int main() {
    int ans = 0;
    int days[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
    REP(i, 12) {
        REP(j, days[i]) {
            if ((j + 1) / 10 + (j + 1) % 10 == i + 1) ans++;
        };
    }

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