#include <iostream>
using namespace std;
int d[] = {31,28,31,30,31,30,31,31,30,31,30,31};

int main() {
  int cnt = 0;
  for (int i = 1; i <= 12; i++) {
    for (int j = 1; j <= d[i-1]; j++) {
      if (i == (j / 10 + j % 10)) {
        cnt++;
      }
    }
  }
  cout << cnt << endl;
}