#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define endl "\n"

int main() {
    int day[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
    int count = 0;

    for (int i = 1; i <= 12; ++i) {
        for (int j = 1; j <= day[i - 1]; ++j) {
            if (i == (int)j / 10 + j % 10) {
                count++;
            }
        }
    }

    cout << count << endl;
    return 0;
}