using System;
using System.Collections.Generic;
using System.Linq;

namespace ConsoleApp17
{
    class Program
    {
        static void Main(string[] args)
        {
            int happyday = 0;
            int dd = 0;

            for (int m=1;m<=12;++m)
            {
                for (int d=1;d<=31;++d)
                {
                    if (m == 2 && 29 <= d)
                    {
                        break;
                    }
                    if ((m == 4 || m == 6 || m == 9 || m == 11) && 31 == d)
                    {
                        break;
                    }

                    if ( 0 <= d && d <=  9) dd = d;
                    if (10 <= d && d <= 19) dd = d - 10 + 1;
                    if (20 <= d && d <= 29) dd = d - 20 + 2;
                    if (30 <= d && d <= 31) dd = d - 30 + 3;

                    if (m == dd) happyday += 1;
                }
                dd = 0;
            }

            Console.WriteLine(happyday);
            Console.ReadLine();

        }
    }
}