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

int main() {
    set<int> short_mo = {4, 6, 9, 11};
    int cnt = 0;
    for (int mm = 1; mm <= 12; mm++) {
        for (int dd = 1; dd <= 31; dd++) {
            if (mm == 2 && dd > 28) continue;
            if (short_mo.count(mm) && dd == 31) continue;
            if (mm == dd / 10 + dd % 10) cnt++;
        }
    }
    cout << cnt << endl;
    return 0;
}