# use strict;
# use warnings;

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

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

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