using System;

namespace yukicoder
{
    class Program
    {
        static void Main(string[] args)
        {
 	    string b="";
            int c = 0;
            int d = 0;
            int count = 0;
            for (int i=1;i<12;i++)
            {
                
                if (i==1||i==3||i==5||i==7||i==8||i==10||i==12)
                {
                    for (int j = 1; j <= 31; j++)
                    {
                        b = j.ToString();
                         c = int.Parse(b.Substring(0,1));
                        if (b.Length == 2)
                        {
                             d = int.Parse(b.Substring(1, 1));
                        }
                        if (i == c + d)
                        {
                            count++;
                        }
                        d = 0;
                    }
                }
                else if (i == 4||i==6||i==9||i==11)
                {
                    for (int j = 1; j <= 30; j++)
                    {
                        b = j.ToString();
                        c = int.Parse(b.Substring(0, 1));
                        if (b.Length == 2)
                        {
                            d = int.Parse(b.Substring(1, 1));
                        }
                        if (i == c + d)
                        {
                            count++;
                        }
                        d = 0;
                    }
                }
                else if (i==2)
                {
                    for (int j = 1; j <= 28; j++)
                    {
                        b = j.ToString();
                        c = int.Parse(b.Substring(0, 1));
                        if (b.Length == 2)
                        {
                            d = int.Parse(b.Substring(1, 1));
                        }
                        if (i == c + d)
                        {
                            count++;
                        }
                        d = 0;
                    }
                }
            }
            Console.WriteLine(count);
        }
    }
}