#include<iostream>
using namespace std;
int main(){
int sum = 0, x[12] = {31,28,31,30,31,30,31,31,30,31,30,31};
for(int i = 0; i < 12; i++){
  for(int j = 0; j < x[i]; j++){
if( i == j/10 + j%10) sum++ ; 
     }
  }
cout  <<  sum << endl;
}