#include<iostream>
#define REP(i,n) for( int i = 1; i <= n; i++ )
using namespace std;
int main(){
  int cnt = 0;
  REP(i,12){
    if( i == 2 || i == 4 || i == 6 || i == 9 || i == 11 )
      REP( j, 30 ) if( (j / 10) + (j % 10) == i ) cnt++;
    else
      REP( j, 31 ) if( (j / 10) + (j % 10) == i ) cnt++;
  }
  cout << cnt << '\n';
}