use strict;

my $N = <STDIN>;
my $str = Fire($N);
my $count = (() = $str =~ /z/g);
print $count."\n";

sub Fire
{
	my $str = "";
	$N = $_[0];
	if($N % 3 == 0 && $N % 5 == 0)
	{
		$str = "FizzBuzz";
	}
	elsif($N % 3 == 0)
	{
		$str = "Fizz";
	}
	elsif($N % 5 == 0)
	{
		$str = "Buzz";
	}
	else
	{
		$str = $N;
	}
	if($N == 1)
	{
		return $str;
	}
	else
	{
		return $str.Fire($N - 1);
	}
}