#include <bits/stdc++.h>
using namespace std;

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

    cout << ans << endl;

    return 0;
}