#include <bits/stdc++.h>
using namespace std;
typedef unsigned long long ul;
typedef signed long long ll;
ul over = 1000000007;

int main(void)
{
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed;
  int month[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
  int ans = 0;
  for (int m = 1; m <= 12; ++m) {
    for (int d = 1; d <= month[m]; ++d) {
      if (m == d/10 + d%10) {
        ans++;
      }
    }
  }
  cout << ans << endl;
  return 0;
}