#include <bits/stdc++.h>
using namespace std;

int main() {
  int ans = 0;
  int d[13] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
  for (int i = 1; i <= 12; i++) {
    for (int j = 1; j <= d[i]; j++) {
      if (i == j / 10 + j % 10) ans++;
    }
  }
  cout << ans << endl;
  return 0;
}