#include <iostream>

#define REP(i, a, b) for (int i = (a); i < (b); i++)
#define dump(s) cerr << __LINE__ << "\t:" << #s << " = " << (s) << endl \
    
using namespace std;

int main () {
    int dlist[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
    int ans = 0;
    REP (i, 0, 12) {
	int month = i + 1;
	REP (date, 1, dlist[i] + 1) {
	    if ((date % 10) + (date / 10) == month) {
		ans++;
		// dump(date);
		// dump(month);
	    }
	}
    }
    cout << ans << endl;
    return 0;
}