highly gifted 12-year-old 
(ROOT (NP (ADJP (RB highly) (VBN gifted)) (ADJP (NP (CD 12) (HYPH -) (NN year)) (HYPH -) (JJ old))))
(ROOT (NP (ADJP (RB ) (VBN )) (ADJP (NP (CD ) (HYPH ) (NN )) (HYPH ) (JJ ))))