How do I show only the parent terms (not the child terms) that a node belongs to in an adapted node.tpl.php file?

Hi there,
I know how to print the taxonomy terms of a node in an adapted node.tpl.php file ( print $terms)
But this is printing out:
child term|parent term

How do I just print out the parent term,
and how do I print the parent term first (i.e. parent term|child term)

Many thanks