#include <iostream>
using namespace std;

int main()
{
  int days[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
  int ans = 0;
  int D;

  for (int m = 0; m < 12; m++)
  {
    int month = m + 1;
    for (int day = 1; day <= days[m]; day++)
    {
      if (day >= 10)
      {
        D = (day / 10) + (day % 10);
      }
      if (month == D) ans++;
    }
  }
  cout << ans << endl;
  return 0;
}