# object1:
sub depth{
	my $self = shift;
	my $max = 0;
	foreach my $item (0 .. 15){
		if(defined($self->{child}->[$item])){
			my $temp = $self->{child}->[$item]->depth; 
			if($temp > $max){
				$max = $temp;
			}
		}
	}
	$self->{myDepth} = $max+1;
	return $max+1;
}

# object2
sub depth{1}