# use strict;
# use warnings;

sub divint {
    my ($x, $y) = @_;
    my $z;
    {
        use integer;
        $z = $x / $y;
    }
    return $z;
}

sub FizzBuzzString {
    my $n = shift;
    return (divint($n, 3) + divint($n, 5)) * 2;
}

chomp(my $N = <>);
print(FizzBuzzString($N), "\n");