#include <iostream>
#include <algorithm>
#include <functional>
#include <string>
#include <climits>
#include <vector>
#include <numeric>
//#define __int32 long long
using namespace std;

//全探索
int main(){
	const int days[] = {31,28,31,30,31,30,31,31,30,31,30,31};
	int ans = 0;
	
	for(int month=0; month<12; month++){
		for(int day=1; day<=days[month]; day++){
			if(day/10 + day%10 == month+1){
				ans++;
			}
		}
	}
	
	cout << ans << endl;
	
    
    return 0;
}