#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

int main(){
	cin.tie(nullptr);
	ios_base::sync_with_stdio(false);
	
	vector<int> day(12);
    day = {31,28,31,30,31,30,31,31,30,31,30,31};
	int cnt = 0;
	for(int i = 1; i <= 12; i++){
		for(int j = 1; j <= day[i-1]; j++){
			int s,f;
			s = j/10;
			f = j%10;
			if(i == s+f) cnt++;
		}
	}
	cout << cnt << endl;
	return 0;
}