#include <bits/stdc++.h>
#define fastIO (cin.tie(0), cout.tie(0), ios::sync_with_stdio(false))
#define precise(i) fixed << setprecision(i)
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
using namespace std;

int main() {
  fastIO;
  int days[12]{
      31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31,
  };

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

  cout << cnt << '\n';
  return 0;
}