#include<bits/stdc++.h>
using namespace std;

int a[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

int main(){

  int ans = 0;
  for(int i=1;i<13;i++){
    for(int j=1;j<=a[i];j++){
      if(i == (j%10 + j/10)){
	ans++;
      }
    }
  }

  cout << ans << endl;

}