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

int main()
{
	int md[12] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
	int ans = 0;
	for( int i = 0; i < 12; i++ ) {
		int m = i + 1;
		for( int d = 1; d <= md[i]; d++ ) {
			int h = d / 10;
			int l = d % 10;
			if( m == h + l ) ans++;
		}
	}

	cout << ans << endl;
}