#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <stack>
#include <algorithm>
#include <string>
#include <map>
#include <iterator>
#include <set>
#include <queue>

using namespace std;

int lastDayOfMonth(int year, int month) {

    if (month == 2) {
        if (year % 400 == 0) {
            return 29;
        } else if (year % 100 == 0) {
            return 28;
        } else if (year % 4 == 0) {
            return 29;
        } else {
            return 28;
        }
    } else {
        switch (month) {
            case 1:
                return 31;
            case 3:
                return 31;
            case 4:
                return 30;
            case 5:
                return 31;
            case 6:
                return 30;
            case 7:
                return 31;
            case 8:
                return 31;
            case 9:
                return 30;
            case 10:
                return 31;
            case 11:
                return 30;
            case 12:
                return 31;

        }
    }
}

int daySum(int day) {

    if (day >= 10) {
        return day / 10 + day % 10;
    } else {
        return day;
    }
}

int main() {

    int count = 0;
    for (int month = 1; month <= 12; ++month) {
        int lastDay = lastDayOfMonth(2015, month);
        for (int day = 1; day <= lastDay; ++day) {
            if (month == daySum(day)) {
                count += 1;
            }
        }
    }


    cout << count << endl;

    return 0;
}