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

int main() { 

    int happyday = 0;
    for(int i = 1; i <= 12; i++){
        if(i == 1 || i == 3 || i == 5 || i == 7 || i == 8 || i == 10 || i == 12){
            for(int j = 1; j <= 31; j++){
                if(i == j/10 + j%10){
                    happyday++;
                }
            }
        }else if(i == 4 || i == 6 || i == 9 || i == 11){
            for(int k = 1; k <= 30; k++){
                if(i == k/10 + k%10){
                    happyday++;
                }
            }
        }else{
            for(int l = 1;l <= 28; l++){
                if(i == l/10 + l%10){
                    happyday++;
                }
            }
        }
    }
    cout << happyday << endl;
}