sub rev ($) {
	$_ = shift;
	s/^(.)(.*)$/swap($2)."$1"/e if (length>1);
#	print "in swap: $_\n";
	return $_;
}

##</code><code>##

sub rev ($) {
	$_ = shift;
	s/^(.)(.*)$/rev($2)."$1"/e if (length>1);
#	print "in rev: $_\n";
	return $_;
}