use strict;
use warnings;

my $a = <>;
my $b = <>;
my $c = <>;

my $normal = ($a / $b) * 2/3;
my $count = $a / $c;

if($count != int $count) {
	$count = int ($count + 1);
}

if($count <= $normal) {
	print "YES\n";
} else {
	print "NO\n";
}

exit;