using System;

public class Program
{
  static void Main()
  {
    int daymax = 0;
    int happyday = 0;
    for (int mon = 1; mon < 13; mon++)
    {
      if (mon == 1 | mon == 3 | mon == 5 | mon == 7 | mon == 8 | mon == 10 | mon == 12)
      {
          daymax = 31;
      }
      else if(mon == 4 | mon == 6 | mon == 9 | mon == 11)
      {
        daymax = 30;
      }
      else if(mon == 2)
      {
        daymax = 28;
      }
      
      for(int day = 1; day < daymax + 1; day++)
      {
        if (day < 10 && day == mon)
        {
          happyday++;
        }
        else if(day > 9)
        {
          string _day = day.ToString();
          int a = Convert.ToInt32(_day.Substring(0,1));
          int b = Convert.ToInt32(_day.Substring(1,1));
          if (a + b == mon)
          {
            happyday++;
          }
        }
      }
    }

    Console.WriteLine(happyday.ToString());
  }
}