#include<iostream>
using namespace std;

int main(){
  int i,j,c=0;
  int day[13]={0, 31,28,31,30,31,30,31,31,30,31,30,31};
  for(i=1;i<=12;i++){
    for(j=1;j<=day[i];j++){
      if(j%10+j/10 == i)c++;
    }
  }

  cout << c << endl;
  
  return 0;
}