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

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