#include <iostream>
#include <vector>

int main() {
	const int M = 12;
	std::vector<int> days = { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
	
	int answer = 0;
	for( int m = 1; m <= 12; m++ ) {
		for( int d = 1; d <= days.at( m ); d++ ) {
			if( d / 10 + d % 10 == m ) {
				answer ++;
			}
		}
	}
	std::cout << answer << std::endl;
	
	return 0;
}