#include <iostream>
#include <vector>
using namespace std;

int main(){
    int c[]={31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
    int cnt = 0;
    for(int i=0; i<12; i++){
        int month = i+1;
        for(int j=1;j<=c[i];j++){
            if(j/10+j%10==month) cnt++;
        }
    }
    cout << cnt << endl;
}