using System;

class Program {
    static void Main() {
        int[] d = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
        int cnt = 0;
        for (int i = 1; i <= 12; i++) {
            for (int j = 1; j <= d[i - 1]; j++) {
                if (i == j / 10 + j % 10) {
                    cnt++;
                } 
            }
        }
        Console.WriteLine(cnt);
    }
}