#include<iostream>
#define REP(i,n) for( int i = 1; i <= n; i++ )
using namespace std;
int main(){
  int cnt = 0;
  int month[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
  REP(i,12)
    REP(j,month[i])
      if( (j/10) + (j%10) == i ) cnt++;
  cout << cnt << '\n';
}