use strict;
use warnings;
use utf8;
use POSIX;

my $count = 0;

for (my $month = 1; $month <= 12; $month++) {
	# 日数決め
	my $max_days;
	if( $month == 2){
		$max_days = 28;
	} elsif (($month == 4) or ($month == 6) or
				($month == 9) or ($month == 11) ) {
		$max_days = 30;
	} else {
		$max_days = 31;
	}
	# カウント処理
	for (my $day = 1; $day <= $max_days; $day++) {
		my $ones_place = $day%10;
		my $tens_place = floor ($day/10);
		# floorで小数部切り捨て
		my $sum = $ones_place + $tens_place;
		if ($sum == $month) {
			$count += 1;
		}
	}
}

print "$count\n";