#include <iostream>
#include <vector>

using namespace std;

int main()
{
	vector<int> m(13);
	m[ 1] = 31;
	m[ 2] = 28;
	m[ 3] = 31;
	m[ 4] = 30;
	m[ 5] = 31;
	m[ 6] = 30;
	m[ 7] = 31;
	m[ 8] = 31;
	m[ 9] = 30;
	m[10] = 31;
	m[11] = 30;
	m[12] = 31;

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