our @matches;

our $code_re;
$code_re = qr{
	(
	\(
	(?: (?>[^()]+) | (??{$code_re}) )*
	\)
	)
	(?{ push @matches, $1 })
}x;


while (<DATA>) {
	chomp;
	@matches = ();
	print /^(?:(?>[^()]+)|$code_re)*$/  ?  'PASS' : (@matches = (), '    ');
	print " $_\n";
	print "       $_\n" foreach @matches;
}