#include <iostream>
using namespace std;

int main(){
	int count =0;
	int day []= {31,28,31,30,31,30,31,31,30,31,30,31};
	for(int i=0 ; i<12 ; i++){
		for(int j=0 ; j < day[i] ; j++){
			if(i + 1== (j % 10)+(j / 10)) count++;
		}
	}
	cout << count << "\n";
}