#include <bits/stdc++.h>

using namespace std;

int main()
{
  int call[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
  int ret = 0;
  for(int i = 1; i <= 12; i++) {
    for(int j = 1; j <= call[i - 1]; j++) {
      if(i == j / 10 + j % 10) ++ret;
    }
  }
  cout << ret << endl;
}