#include <iostream>
#include <list>
#include <vector>
#include <string>
#include <stdio.h>
#include <stdint.h>
using namespace std;

using uint = unsigned int;
using ll = long long;

#define CIN( LL , A ) LL A; cin >> A 
#define GETLINE( A ) string A; getline( cin , A ) 

int main()
{

  const ll day[13] = { 0 , 31 , 28 , 31 , 30 , 31 , 30 , 31 , 31 , 30 , 31 , 30 , 31 };
  ll num = 0;
  
  for( ll i = 1 ; i <= 12 ; i++ ){

    const ll& day_i = day[i];

    for( ll j = 1 ; j <= day_i ; j++ ){

      if( i == j / 10 + j % 10 ){

	num++;

      }

    }
    
  }

  cout << num << endl;
  return 0;

}