#include <algorithm>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <ctime>
#include <iostream>
#include <sstream>
#include <functional>
#include <map>
#include <string>
#include <cstring>
#include <vector>
#include <queue>
#include <stack>
#include <deque>
#include <set>
#include <list>
#include <numeric>
using namespace std;
const double PI = 3.14159265358979323846;
const double EPS = 1e-12;
const int INF = 1<<25;
typedef pair<int,int> P;
typedef long long ll;
typedef unsigned long long ull;

int d[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30};

int main(){
	int res = 0;
	for(int i = 0;  i < 12; i++){
		int m = i+1;
		for(int j = 1; j <= d[i]; j++){
			int k = j/10 + j%10;
			if(m==k) res++;
		}
	}
	cout<<res<<endl;
	return 0;
}